Sang Hyun Park

Prof. Sang Hyun Park

Daegu Gyeongbuk Institute of Science and Technology (DGIST)
orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

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

Representative Publications

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7 October 2022 in Frontiers in Plant Science
Verified
Journal Article
Open access
MSMuhammad Shoaib
Muhammad Shoaib
Tariq HussainTariq Hussain
Tariq Hussain
BSBabar Shah
Babar Shah
IUIhsan Ullah
Ihsan Ullah
SSSayyed Mudassar Shah
Sayyed Mudassar Shah
Sang Hyun ParkSang Hyun Park
Sang Hyun Park
Plants contribute significantly to the global food supply. Various Plant diseases can result in production losses, which can be avoided by maintaining vigilance. However, manually monitoring plant diseases by agriculture experts and botanists is time-consuming, challenging and error-prone. To reduce the risk of disease severity, machine vision technology (i.e., artificial intelligence) can play a significant role. In the alternative method, the severity of the disease can be diminished through computer technologies and the cooperation of humans. These methods can also eliminate the disadvantages of manual observation. In this work, we proposed a solution to detect tomato plant disease using a deep leaning-based system utilizing the plant leaves image data. We utilized an architecture for deep learning based on a recently developed convolutional neural network that is trained over 18,161 segmented and non-segmented tomato leaf images—using a supervised learning approach to detect and recognize various tomato diseases using the Inception Net model in the research work. For the detection and segmentation of disease-affected regions, two state-of-the-art semantic segmentation models, i.e., U-Net and Modified U-Net, are utilized in this work. The plant leaf pixels are binary and classified by the model as Region of Interest (ROI) and background. There is also an examination of the presentation of binary arrangement (healthy and diseased leaves), six-level classification (healthy and other ailing leaf groups), and ten-level classification (healthy and other types of ailing leaves) models. The Modified U-net segmentation model outperforms the simple U-net segmentation model by 98.66 percent, 98.5 IoU score, and 98.73 percent on the dice. InceptionNet1 achieves 99.95% accuracy for binary classification problems and 99.12% for classifying six segmented class images; InceptionNet outperformed the Modified U-net model to achieve higher accuracy. The experimental results of our proposed method for classifying plant diseases demonstrate that it outperforms the methods currently available in the literature.

29 September 2020
Verified
Book Chapter
Closed access
PDF file
PCPHILIP CHIKONTWE
PHILIP CHIKONTWE
MKMeejeong Kim
Meejeong Kim
SNSoo Jeong Nam
Soo Jeong Nam
HGHeounjeong Go
Heounjeong Go
Sang Hyun ParkSang Hyun Park
Sang Hyun Park

26 November 2021 in Scientific Reports
Verified
Journal Article
Open access
PDF file
GRGahyung Ryu
Gahyung Ryu
KLKyungmin Lee
Kyungmin Lee
DPDonggeun Park
Donggeun Park
Sang Hyun ParkSang Hyun Park
Sang Hyun Park
MSMin Sagong
Min Sagong
As the prevalence of diabetes increases, millions of people need to be screened for diabetic retinopathy (DR). Remarkable advances in technology have made it possible to use artificial intelligence to screen DR from retinal images with high accuracy and reliability, resulting in reducing human labor by processing large amounts of data in a shorter time. We developed a fully automated classification algorithm to diagnose DR and identify referable status using optical coherence tomography angiography (OCTA) images with convolutional neural network (CNN) model and verified its feasibility by comparing its performance with that of conventional machine learning model. Ground truths for classifications were made based on ultra-widefield fluorescein angiography to increase the accuracy of data annotation. The proposed CNN classifier achieved an accuracy of 91–98%, a sensitivity of 86–97%, a specificity of 94–99%, and an area under the curve of 0.919–0.976. In the external validation, overall similar performances were also achieved. The results were similar regardless of the size and depth of the OCTA images, indicating that DR could be satisfactorily classified even with images comprising narrow area of the macular region and a single image slab of retina. The CNN-based classification using OCTA is expected to create a novel diagnostic workflow for DR detection and referral.

9 January 2020 in Spine
Verified
Journal Article
Closed access
DWDongkyu Bs Won
Dongkyu Bs Won
HLHyun-Joo Lee
Hyun-Joo Lee
SLSuk Joong Lee
Suk Joong Lee
Sang Hyun ParkSang Hyun Park
Sang Hyun Park
Study Design.: Retrospective magnetic resonance imaging grading with comparison between experts and deep convolutional neural networks (CNNs). Objective.: This study aims to verify the feasibility of a computer-assisted spine stenosis grading system by comparing the diagnostic agreement between two experts and the agreement between the experts and trained artificial CNN classifiers. Summary of Background Data.: Spinal stenosis grading is important; however, it is tedious job to check the MR images slide by slide to classify patient grades often having different opinions regarding the final diagnosis. Methods.: For 542 L4-5 axial MR images, two experts independently localized the center position of the spine canal and graded the status. Two CNN classifiers each trained with the grading label made by the two experts were validated using 10-fold cross-validation. Each classifier consisted of a CNN detection model responsible for the localization of patches near the canal and a classification CNN model to predict the spinal stenosis status in the localized patches. Faster R-CNN was used for the detection model whereas VGG network was used for the classification model. A comparison in grading agreement was carried out between the two experts as well as that of the experts and the prediction results generated by the CNN models. Results.: Grading agreement between the experts was 77.5% and 75% in terms of accuracy and F1 scores. The agreement between the first expert and the model trained with the labels of the first expert was 83% and 75.4%, respectively. The agreement between the second expert and the model trained with the labels of the second expert was 77.9% and 74.9%. The differences between the two experts were significant, whereas the differences between each expert and the trained models were not significant. Conclusion.: We indeed confirmed that automatic diagnosis using deep learning may be feasible for spinal stenosis grading. Level of Evidence: 4


1 October 2023
Verified
Book Chapter
Closed access
PDF file
WPWei Peng
Wei Peng
EMEhsan Adeli Mosabbeb
Ehsan Adeli Mosabbeb
TBTomas Bosschieter
Tomas Bosschieter
Sang Hyun ParkSang Hyun Park
Sang Hyun Park
QZQingyu Zhao
Qingyu Zhao
KPKilian Maria Pohl
Kilian Maria Pohl