Yiheng Cai

Dr. Yiheng Cai

orcid

Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

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

Representative Publications

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16 April 2019 in IEEE Access
Verified
Journal Article
Open access
YCYiheng Cai
Yiheng Cai
YLYuanyuan Li
Yuanyuan Li
CQChangyan Qiu
Changyan Qiu
JMJie Ma
Jie Ma
XGXurong Gao
Xurong Gao

20 November 2019 in IEEE Access
Verified
Journal Article
Open access
YLYuanyuan Li
Yuanyuan Li
YCYiheng Cai
Yiheng Cai
JLJiaqi Liu
Jiaqi Liu
Shinan LangShinan Lang
Shinan Lang
XZXinfeng Zhang
Xinfeng Zhang
Anomaly detection in video surveillance is challenging due to the variety of anomaly types and definitions, which limit the use of supervised techniques. As such, auto-encoder structures, a type of classical unsupervised method, have recently been utilized in this field. These structures consist of an encoder followed by a decoder and are typically adopted to restructure a current input frame or predict a future frame. However, regardless of whether a 2D or 3D autoencoder structure is adopted, only single-scale information from the previous layer is typically used in the decoding process. This can result in a loss of detail that could potentially be used to predict or reconstruct video frames. As such, this study proposes a novel spatio–temporal U-Net for frame prediction using normal events and abnormality detection using prediction error. This framework combines the benefits of U-Nets in representing spatial information with the capabilities of ConvLSTM for modeling temporal motion data. In addition, we propose a new regular score function, consisting of a prediction error for not only the current frame but also future frames, to further improve the accuracy of anomaly detection. Extensive experiments on common anomaly datasets, including UCSD (98 video clips in total) and CUHK Avenue (30 video clips in total), validated the performance of the proposed technique and we achieved 96.5% AUC for the Ped2 dataset, which is much better than existing autoencoder-based and U-Net-based methods.

5 April 2020 in Applied Sciences
Verified
Journal Article
Open access
PDF file
YCYiheng Cai
Yiheng Cai
SHShaobin Hu
Shaobin Hu
Shinan LangShinan Lang
Shinan Lang
YGYajun Guo
Yajun Guo
JLJiaqi Liu
Jiaqi Liu
Sea level rise, caused by the accelerated melting of glaciers in Greenland and Antarctica in recent decades, has become a major concern in the scientific, environmental, and political arenas. A comprehensive study of the properties of the ice subsurface targets is particularly important for a reliable analysis of their future evolution. Newer deep learning techniques greatly outperform the traditional techniques based on hand-crafted feature engineering. Therefore, we propose an efficient end-to-end network for the automatic classification of ice sheet subsurface targets in radar imagery. Our network uses bilateral filtering to reduce noise and consists of ResNet module, improved Atrous Spatial Pyramid Pooling (ASPP) module, and decoder module. With radar images provided by the Center of Remote Sensing of Ice Sheets (CReSIS) from 2009 to 2011 as our training and testing data, experimental results confirm the robustness and effectiveness of the proposed network in radargram.

9 April 2024 in IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Verified
Journal Article
Open access
KHKaiqi He
Kaiqi He
YCYiheng Cai
Yiheng Cai
SPShengjun Peng
Shengjun Peng
MTMeiling Tan
Meiling Tan
Hyperspectral images (HSIs) can reflect the spectral characteristics of objects in multiple bands, which can be used in various tasks, including classification, material detection and identification, and geological exploration. However, due to hardware limitations, spatial data have commonly been partially discarded to obtain more spectral information. Therefore, the enhancement of spatial resolution is often contemplated through the application of super-resolution algorithms. In view of this, this study proposes a diffusion model-assisted multiscale spectral attention network (DMSANet) to increase the HSI resolution in the spatial dimension while preserving spectral information as much as possible. For the first time, a diffusion model is combined with deep networks to solve the HSI super-resolution problem, which enhances the spatial texture details of the output image using a layer-by-layer super-resolution mechanism of Markov chains. In addition, a multiscale attention block that can integrate multiple receptive fields to extract spectral features of HSIs is designed, which enhances spectral information details. Extensive evaluations and comparisons on three benchmark datasets demonstrate that the proposed DMSANet can achieve superior performance compared with the existing methods.

10 July 2024 in Sensors
Verified
Journal Article
Open access
PDF file
JWJiaze Wu
Jiaze Wu
LJLi Zi Jian
Li Zi Jian
YCYiheng Cai
Yiheng Cai
HLHao Liang
Hao Liang
LZLong Zhou
Long Zhou
JGJing Guan
Jing Guan
Background: As an important part of the tongue, the tongue coating is closely associated with different disorders and has major diagnostic benefits. This study aims to construct a neural network model that can perform complex tongue coating segmentation. This addresses the issue of tongue coating segmentation in intelligent tongue diagnosis automation. Method: This work proposes an improved TransUNet to segment the tongue coating. We introduced a transformer as a self-attention mechanism to capture the semantic information in the high-level features of the encoder. At the same time, the subtraction feature pyramid (SFP) and visual regional enhancer (VRE) were constructed to minimize the redundant information transmitted by skip connections and improve the spatial detail information in the low-level features of the encoder. Results: Comparative and ablation experimental findings indicate that our model has an accuracy of 96.36%, a precision of 96.26%, a dice of 96.76%, a recall of 97.43%, and an IoU of 93.81%. Unlike the reference model, our model achieves the best segmentation effect. Conclusion: The improved TransUNet proposed here can achieve precise segmentation of complex tongue images. This provides an effective technique for the automatic extraction in images of the tongue coating, contributing to the automation and accuracy of tongue diagnosis.

28 February 2023 in Remote Sensing
Verified
Journal Article
Open access
PDF file
YCYiheng Cai
Yiheng Cai
FWFuxing Wan
Fuxing Wan
Shinan LangShinan Lang
Shinan Lang
Xiangbin CuiXiangbin Cui
Xiangbin Cui
ZYZijun Yao
Zijun Yao
Bed topography and roughness play important roles in numerous ice-sheet analyses. Although the coverage of ice-penetrating radar measurements has vastly increased over recent decades, significant data gaps remain in certain areas of subglacial topography and need interpolation. However, the bed topography generated by interpolation such as kriging and mass conservation is generally smooth at small scales, lacking topographic features important for sub-kilometer roughness. DeepBedMap, a deep learning method combined with multiple surface observation inputs, can generate high-resolution (250 m) bed topography with realistic bed roughness but produces some unrealistic artifacts and higher bed elevation values in certain regions, which could bias ice-sheet models. To address these issues, we present MB_DeepBedMap, a multi-branch deep learning method to generate more realistic bed topography. The model improves upon DeepBedMap by separating inputs into two groups using a multi-branch network structure according to their characteristics, rather than fusing all inputs at an early stage, to reduce artifacts in the generated topography caused by earlier fusion of inputs. A direct upsampling branch preserves large-scale subglacial landforms while generating high-resolution bed topography. We use MB_DeepBedMap to generate a high-resolution (250 m) bed elevation grid product of Antarctica, MB_DeepBedMap_DEM, which can be used in high-resolution ice-sheet modeling studies. Moreover, we test the performance of MB_DeepBedMap model in Thwaites Glacier, Gamburtsev Subglacial Mountains, and several other regions, by comparing the qualitative topographic features and quantitative errors of MB_DeepBedMap, BEDMAP2, BedMachine Antarctica, and DeepBedMap. The results show that MB_DeepBedMap can provide more realistic small-scale topographic features and roughness compared to BEDMAP2, BedMachine Antarctica, and DeepBedMap.