Nan Wang

Prof. Nan Wang


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 October 2020 in Frontiers in Plant Science
Verified
Journal Article
Open access
PDF file
CSChen Shen
Chen Shen
LLLiantao Liu
Liantao Liu
LZLingxiao Zhu
Lingxiao Zhu
JKJia Kang
Jia Kang
NWNan Wang
Nan Wang
LSLimin Shao
Limin Shao
The Rhizotrons method is an important means of detecting dynamic growth and development phenotypes of plant roots. However, the segmentation of root images is a critical obstacle restricting further development of this method. At present, researchers mostly use direct manual drawings or software-assisted manual drawings to segment root systems for analysis. Root systems can be segmented from root images obtained by the Rhizotrons method, and then, root system lengths and diameters can be obtained with software. This type of image segmentation method is extremely inefficient and very prone to human error. Here, we investigate the effectiveness of an automated image segmentation method based on the DeepLabv3+ convolutional neural network (CNN) architecture to streamline such measurements. We have improved the upsampling portion of the DeepLabv3+ network and validated it using in situ images of cotton roots obtained with a micro root window root system monitoring system. Segmentation performance of the proposed method utilizing WinRHIZO Tron MF analysis was assessed using these images. After 80 epochs of training, the final verification set F1-score, recall, and precision were 0.9773, 0.9847, and 0.9702, respectively. The Spearman rank correlation between the manually obtained Rhizotrons manual segmentation root length and automated root length was 0.9667 (p < 10–8), with r2 = 0.9449. Based on the comparison of our segmentation results with those of traditional manual and U-net segmentation methods, this novel method can more accurately segment root systems in complex soil environments. Thus, using the improved DeepLabv3+ to segment root systems based on micro-root images is an effective method for accurately and quickly segmenting root systems in a homogeneous soil environment and has clear advantages over traditional manual segmentation.

28 November 2019 in IEEE Access
Verified
Journal Article
Open access
YFYimeng Fan
Yimeng Fan
HJHao Jin
Hao Jin
YGYongzhe Ge
Yongzhe Ge
NWNan Wang
Nan Wang
With the development of the Internet of Things technology and the continuous improvement of manufacturing processes, smart devices continue to evolve. In the existing research on human motion posture detection, there are relatively few portable wearable devices. Therefore, research on human motion posture detection based on smart wearable devices will be an important direction for future development. In this paper, a smart phone with a built-in triaxial acceleration sensor is used as a data acquisition facility to simulate the wearable device’s experiment on the daily movement of the human body. The threedimensional acceleration data during the motion is collected, and the related methods are proposed to detect the human body motion posture, and further analyze the transition between various postures, and detect the special fall posture. Starting from the two aspects of time domain and frequency domain, the analysis algorithm of human motion attitude detection is expounded. Using the time domain algorithm to detect the current motion posture of the human body, the current motion posture of the human body can be quickly detected. However, if we simply use time-domain-based detection methods, it is easy to cause errors in attitude detection. In order to improve this detection error, we combine the frequency domain analysis method, use the acceleration modulus algorithm and perform FFT (Fast Fourier Transformation) to analyze the frequency domain characteristics of the signal to distinguish the human body’s motion posture and improve the basic daily posture detection of the human body. The results show that the proposed method can eliminate large noise interference and reduce the missed rate and false positive rate of human attitude detection.

15 June 2023 in Plant Phenomics
Verified
Journal Article
Open access
QYQiushi Yu
Qiushi Yu
JWJingqi Wang
Jingqi Wang
HTHui Tang
Hui Tang
JZJiaxi Zhang
Jiaxi Zhang
WZWenjie Zhang
Wenjie Zhang
NWNan Wang
Nan Wang
The root is an important organ for crops to absorb water and nutrients. Complete and accurate acquisition of root phenotype information is important in root phenomics research. The in situ root research method can obtain root images without destroying the roots. In the image, some of the roots are vulnerable to soil shading, which severely fractures the root system and diminishes its structural integrity. The methods of ensuring the integrity of in situ root identification and establishing in situ root image phenotypic restoration remain to be explored. Therefore, based on the in situ root image of cotton, this study proposes a root segmentation and reconstruction strategy, improves the UNet model, and achieves precise segmentation. It also adjusts the weight parameters of EnlightenGAN to achieve complete reconstruction and employs transfer learning to implement enhanced segmentation using the results of the former two. The research results show that the improved UNet model has an accuracy of 99.2%, mIOU of 87.03%, and F1 of 92.63%. The root reconstructed by EnlightenGAN after direct segmentation has an effective reconstruction ratio of 92.46%. This study enables a transition from supervised to unsupervised training of root system reconstruction by designing a combination strategy of segmentation and reconstruction network. It achieves the integrity restoration of in situ root system pictures and offers a fresh approach to studying the phenotypic of in situ root systems, also realizes the restoration of the integrity of the in situ root image, and provides a new method for in situ root phenotype study.

1 March 2024 in Plant Phenomics
Verified
Journal Article
Open access
HTHui Tang
Hui Tang
XCXue Cheng
Xue Cheng
QYQiushi Yu
Qiushi Yu
JZJiaXi Zhang
JiaXi Zhang
NWNan Wang
Nan Wang
LLLiantao Liu
Liantao Liu
The root is an important organ for plants to obtain nutrients and water, and its phenotypic characteristics are closely related to its functions. Deep-learning-based high-throughput in situ root senescence feature extraction has not yet been published. In light of this, this paper suggests a technique based on the transformer neural network for retrieving cotton’s in situ root senescence properties. High-resolution in situ root pictures with various levels of senescence are the main subject of the investigation. By comparing the semantic segmentation of the root system by general convolutional neural networks and transformer neural networks, SegFormer-UN (large) achieves the optimal evaluation metrics with mIoU, mRecall, mPrecision, and mF1 metric values of 81.52%, 86.87%, 90.98%, and 88.81%, respectively. The segmentation results indicate more accurate predictions at the connections of root systems in the segmented images. In contrast to 2 algorithms for cotton root senescence extraction based on deep learning and image processing, the in situ root senescence recognition algorithm using the SegFormer-UN model has a parameter count of 5.81 million and operates at a fast speed, approximately 4 min per image. It can accurately identify senescence roots in the image. We propose that the SegFormer-UN model can rapidly and nondestructively identify senescence root in in situ root images, providing important methodological support for efficient crop senescence research.

12 December 2024 in Advanced Science
Verified
Journal Article
Open access
QYQiushi Yu
Qiushi Yu
MZMeng Zhang
Meng Zhang
LWLiuli Wang
Liuli Wang
XLXingyun Liu
Xingyun Liu
LZLingxiao Zhu
Lingxiao Zhu
NWNan Wang
Nan Wang
Root systems are crucial organs for crops to absorb water and nutrients. Conducting phenotypic analysis on roots is of great importance. To date, methods for root system phenotypic analysis have predominantly focused on semantic segmentation, integrating phenotypic extraction software to achieve comprehensive root phenotype analysis. This study demonstrates the feasibility of instance segmentation tasks on in situ root system images. An improved YoloV8n‐seg network tailored for detecting elongated roots is proposed, which outperforms the original YoloV8seg in all network performance metrics. Additionally, the post‐processing method introduced reduces root identification errors, ensuring a one‐to‐one correspondence between each root system and its detection box. The experiment yields phenotypic parameters for fine‐grained roots, such as fine‐grained root length, diameter, and curvature. Compared to traditional parameters like total root length and average root diameter, these detailed phenotypic analyses enable more precise phenotyping and facilitate accurate artificial intervention during crop cultivation.

17 February 2023 in Frontiers in Plant Science
Verified
Journal Article
Open access
QYQiushi Yu
Qiushi Yu
HTHui Tang
Hui Tang
LZLingxiao Zhu
Lingxiao Zhu
WZWenjie Zhang
Wenjie Zhang
LLLiantao Liu
Liantao Liu
NWNan Wang
Nan Wang
The root is an important organ for plants to absorb water and nutrients. In situ root research method is an intuitive method to explore root phenotype and its change dynamics. At present, in situ root research, roots can be accurately extracted from in situ root images, but there are still problems such as low analysis efficiency, high acquisition cost, and difficult deployment of image acquisition devices outdoors. Therefore, this study designed a precise extraction method of in situ roots based on semantic segmentation model and edge device deployment. It initially proposes two data expansion methods, pixel by pixel and equal proportion, expand 100 original images to 1600 and 53193 respectively. It then presents an improved DeeplabV3+ root segmentation model based on CBAM and ASPP in series is designed, and the segmentation accuracy is 93.01%. The root phenotype parameters were verified through the Rhizo Vision Explorers platform, and the root length error was 0.669%, and the root diameter error was 1.003%. It afterwards designs a time-saving Fast prediction strategy. Compared with the Normal prediction strategy, the time consumption is reduced by 22.71% on GPU and 36.85% in raspberry pie. It ultimately deploys the model to Raspberry Pie, realizing the low-cost and portable root image acquisition and segmentation, which is conducive to outdoor deployment. In addition, the cost accounting is only $247. It takes 8 hours to perform image acquisition and segmentation tasks, and the power consumption is as low as 0.051kWh. In conclusion, the method proposed in this study has good performance in model accuracy, economic cost, energy consumption, etc. This paper realizes low-cost and high-precision segmentation of in-situ root based on edge equipment, which provides new insights for high-throughput field research and application of in-situ root.