Wonjoon Kim

Prof. Dr. Wonjoon Kim

Department of Industrial and Management Engineering, Sungkyul University, Seoul, Korea
orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

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18 April 2021 in Sensors
Verified
Journal Article
Open access
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Parvathaneni Naga SrinivasuParvathaneni Naga Srinivasu
Parvathaneni Naga Srinivasu
Jalluri Gnana SivaSaiJalluri Gnana SivaSai
Jalluri Gnana SivaSai
MIMuhammad Fazal Ijaz
Muhammad Fazal Ijaz
AKASH KUMAR BHOIAKASH KUMAR BHOI
AKASH KUMAR BHOI
Wonjoon KimWonjoon Kim
Wonjoon Kim
James Jin KangJames Jin Kang
James Jin Kang
Deep learning models are efficient in learning the features that assist in understanding complex patterns precisely. This study proposed a computerized process of classifying skin disease through deep learning based MobileNet V2 and Long Short Term Memory (LSTM). The MobileNet V2 model proved to be efficient with a better accuracy that can work on lightweight computational devices. The proposed model is efficient in maintaining stateful information for precise predictions. A grey-level co-occurrence matrix is used for assessing the progress of diseased growth. The performance has been compared against other state-of-the-art models such as Fine-Tuned Neural Networks (FTNN), Convolutional Neural Network (CNN), Very Deep Convolutional Networks for Large-Scale Image Recognition developed by Visual Geometry Group (VGG), and convolutional neural network architecture that expanded with few changes. The HAM10000 dataset is used and the proposed method has outperformed other methods with more than 85% accuracy. Its robustness in recognizing the affected region much faster with almost 2× lesser computations than the conventional MobileNet model results in minimal computational efforts. Furthermore, a mobile application is designed for instant and proper action. It helps the patient and dermatologists identify the type of disease from the affected region’s image at the initial stage of the skin disease. These findings suggest that the proposed system can help general practitioners efficiently and effectively diagnose skin conditions, thereby reducing further complications and morbidity.

7 June 2022 in Biosensors
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Journal Article
Open access
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Debarshi BhattacharyaDebarshi Bhattacharya
Debarshi Bhattacharya
DSDEEPAK SHARMA
DEEPAK SHARMA
Wonjoon KimWonjoon Kim
Wonjoon Kim
MIMuhammad Fazal Ijaz
Muhammad Fazal Ijaz
PSPawan Kumar Singh
Pawan Kumar Singh
Biomedical images contain a huge number of sensor measurements that can provide disease characteristics. Computer-assisted analysis of such parameters aids in the early detection of disease, and as a result aids medical professionals in quickly selecting appropriate medications. Human Activity Recognition, abbreviated as ‘HAR’, is the prediction of common human measurements, which consist of movements such as walking, running, drinking, cooking, etc. It is extremely advantageous for services in the sphere of medical care, such as fitness trackers, senior care, and archiving patient information for future use. The two types of data that can be fed to the HAR system as input are, first, video sequences or images of human activities, and second, time-series data of physical movements during different activities recorded through sensors such as accelerometers, gyroscopes, etc., that are present in smart gadgets. In this paper, we have decided to work with time-series kind of data as the input. Here, we propose an ensemble of four deep learning-based classification models, namely, ‘CNN-net’, ‘CNNLSTM-net’, ‘ConvLSTM-net’, and ‘StackedLSTM-net’, which is termed as ‘Ensem-HAR’. Each of the classification models used in the ensemble is based on a typical 1D Convolutional Neural Network (CNN) and Long Short-Term Memory (LSTM) network; however, they differ in terms of their architectural variations. Prediction through the proposed Ensem-HAR is carried out by stacking predictions from each of the four mentioned classification models, then training a Blender or Meta-learner on the stacked prediction, which provides the final prediction on test data. Our proposed model was evaluated over three benchmark datasets, WISDM, PAMAP2, and UCI-HAR; the proposed Ensem-HAR model for biomedical measurement achieved 98.70%, 97.45%, and 95.05% accuracy, respectively, on the mentioned datasets. The results from the experiments reveal that the suggested model performs better than the other multiple generated measurements to which it was compared.

1 May 2020 in Applied Ergonomics
Verified
Journal Article
Closed access
Wonjoon KimWonjoon Kim
Wonjoon Kim
NKNayoung Kim
Nayoung Kim
JLJoseph B. Lyons
Joseph B. Lyons
CNChang Nam
Chang Nam

1 January 2019 in Applied Ergonomics
Verified
Journal Article
Closed access
Wonjoon KimWonjoon Kim
Wonjoon Kim
TKTaehoon Ko
Taehoon Ko
IRIlsun Rhiu
Ilsun Rhiu
MYMyung Hwan Yun
Myung Hwan Yun

9 February 2023 in Applied Artificial Intelligence
Verified
Journal Article
Open access
SCSanghyun Choo
Sanghyun Choo
Wonjoon KimWonjoon Kim
Wonjoon Kim
The present study aims to compare and analyze the performance of two tokenizers, Mecab-Ko and SentencePiece, in the context of natural language processing for sentiment analysis. The study adopts a comparative approach, employing five algorithms - Naive Bayes (NB), k-Nearest Neighbor (kNN), Support Vector Machine (SVM), Artificial Neural Networks (ANN), and Long Short-Term Memory Recurrent Neural Networks (LSTM-RNN) - to evaluate the performance of each tokenizer. The performance was assessed based on four widely used metrics in the field, accuracy, precision, recall, and F1-score. The results indicated that SentencePiece performed better than Mecab-Ko. To ensure the validity of the results, paired t-tests were conducted on the evaluation outcomes. The study concludes that SentencePiece demonstrated superior classification performance, especially in the context of ANN and LSTM-RNN, when used to interpret customer sentiment based on Korean online reviews. Furthermore, SentencePiece can assign specific meanings to short words or jargon commonly used in product evaluations but not defined beforehand.

1 August 2018 in Applied Sciences
Verified
Journal Article
Open access
PDF file
YKYong Min Kim
Yong Min Kim
Youngdoo SonYoungdoo Son
Youngdoo Son
Wonjoon KimWonjoon Kim
Wonjoon Kim
BJByungki Jin
Byungki Jin
MYMyung Hwan Yun
Myung Hwan Yun
Sitting on a chair in an awkward posture or sitting for a long period of time is a risk factor for musculoskeletal disorders. A postural habit that has been formed cannot be changed easily. It is important to form a proper postural habit from childhood as the lumbar disease during childhood caused by their improper posture is most likely to recur. Thus, there is a need for a monitoring system that classifies children’s sitting postures. The purpose of this paper is to develop a system for classifying sitting postures for children using machine learning algorithms. The convolutional neural network (CNN) algorithm was used in addition to the conventional algorithms: Naïve Bayes classifier (NB), decision tree (DT), neural network (NN), multinomial logistic regression (MLR), and support vector machine (SVM). To collect data for classifying sitting postures, a sensing cushion was developed by mounting a pressure sensor mat (8 × 8) inside children’s chair seat cushion. Ten children participated, and sensor data was collected by taking a static posture for the five prescribed postures. The accuracy of CNN was found to be the highest as compared with those of the other algorithms. It is expected that the comprehensive posture monitoring system would be established through future research on enhancing the classification algorithm and providing an effective feedback system.