Byung Wook Kim

Dr. Byung Wook Kim

Changwon National University
orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

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

Representative Publications

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19 November 2021 in Applied Sciences
Verified
Journal Article
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Lakpa TamangLakpa Tamang
Lakpa Tamang
Byung Wook KimByung Wook Kim
Byung Wook Kim
Unprecedented breakthroughs in the development of graphical processing systems have led to great potential for deep learning (DL) algorithms in analyzing visual anatomy from high-resolution medical images. Recently, in digital pathology, the use of DL technologies has drawn a substantial amount of attention for use in the effective diagnosis of various cancer types, especially colorectal cancer (CRC), which is regarded as one of the dominant causes of cancer-related deaths worldwide. This review provides an in-depth perspective on recently published research articles on DL-based CRC diagnosis and prognosis. Overall, we provide a retrospective synopsis of simple image-processing-based and machine learning (ML)-based computer-aided diagnosis (CAD) systems, followed by a comprehensive appraisal of use cases with different types of state-of-the-art DL algorithms for detecting malignancies. We first list multiple standardized and publicly available CRC datasets from two imaging types: colonoscopy and histopathology. Secondly, we categorize the studies based on the different types of CRC detected (tumor tissue, microsatellite instability, and polyps), and we assess the data preprocessing steps and the adopted DL architectures before presenting the optimum diagnostic results. CRC diagnosis with DL algorithms is still in the preclinical phase, and therefore, we point out some open issues and provide some insights into the practicability and development of robust diagnostic systems in future health care and oncology.

28 October 2022 in Applied Sciences
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Journal Article
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NMNilesh Maharjan
Nilesh Maharjan
NDNikesh Devkota
Nikesh Devkota
Byung Wook KimByung Wook Kim
Byung Wook Kim
Free space optical (FSO) communications have the potential to be one of the most essential technologies for solving the high-bandwidth demands of communications between satellites and ground stations. In this study, we examine the impact of the atmosphere on satellite–ground FSO uplink and downlink communications. To consider diverse atmospheric conditions on both uplink and downlink, we derive FSO channel elements such as the fog attenuation coefficient, refractive index parameter, coherence length, turbulence model, and angle-of-arrival fluctuation. Unlike conventional work, we provide FSO channel analysis based on variations in the Fried parameter, zenith angle, scintillation index, and Rytov variance. Using simulation results from the optical settings, we examine the influence on channel performance of conditions such as atmospheric attenuation and intensity fluctuation. Based on this examination, we determine that 1550 nm is the preferred wavelength for both uplink and downlink FSO channels to mitigate the impact of turbulence and that larger receiver apertures lessen angle-of-arrival changes.

25 January 2024 in Electronics
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Journal Article
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NDNikesh Devkota
Nikesh Devkota
Byung Wook KimByung Wook Kim
Byung Wook Kim
This paper proposes SE-DenseNet-HP, a novel finger vein recognition model that integrates DenseNet with a squeeze-and-excitation (SE)-based channel attention mechanism and a hybrid pooling (HP) mechanism. To distinctively separate the finger vein patterns from their background, original finger vein images are preprocessed using region-of-interest (ROI) extraction, contrast enhancement, median filtering, adaptive thresholding, and morphological operations. The preprocessed images are then fed to SE-DenseNet-HP for robust feature extraction and recognition. The DenseNet-based backbone improves information flow by enhancing feature propagation and encouraging feature reuse through feature map concatenation. The SE module utilizes a channel attention mechanism to emphasize the important features related to finger vein patterns while suppressing less important ones. HP architecture used in the transitional blocks of SE-DenseNet-HP concatenates the average pooling method with a max pooling strategy to preserve both the most discriminative and contextual information. SE-DenseNet-HP achieved recognition accuracy of 99.35% and 93.28% on the good-quality FVUSM and HKPU datasets, respectively, surpassing the performance of existing methodologies. Additionally, it demonstrated better generalization performance on the FVUSM, HKPU, UTFVP, and MMCBNU_6000 datasets, achieving remarkably low equal error rates (EERs) of 0.03%, 1.81%, 0.43%, and 1.80%, respectively.

29 March 2021 in Optics Express
Verified
Journal Article
Closed access
Lakpa TamangLakpa Tamang
Lakpa Tamang
Byung Wook KimByung Wook Kim
Byung Wook Kim
In this paper, we propose Deep D2C-Net, a novel display-to-camera (D2C) communications technique using deep convolutional neural networks (DCNNs) for data embedding and extraction with images. The proposed technique consists of fully end-to-end encoding and decoding networks, which respectively produce high-quality data-embedded images and enable robust data acquisition in the presence of optical wireless channel. For encoding, Hybrid layers are introduced where the concurrent feature maps of the intended data and cover images are concatenated in a feed-forward fashion; for decoding, a simple convolutional neural network (CNN) is utilized. We conducted experiments in a real-world environment using a smartphone camera and a digital display with multiple parameters, such as transmission distance, capture angle, display brightness, and resolution of the camera. Experimental results prove that Deep D2C-Net outperforms the existing state-of-the-art algorithms in terms of peak signal-to-noise ratio (PSNR) and bit error rate (BER), while the data-embedded image displayed on the screen yields high visual quality for the human eye.

12 November 2021 in Cancers
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Byung Wook KimByung Wook Kim
Byung Wook Kim
Min Chul ChoiMin Chul Choi
Min Chul Choi
Min Kyu KimMin Kyu Kim
Min Kyu Kim
JLJeong-Won Lee
Jeong-Won Lee
MKMin Tae Kim
Min Tae Kim
CLChan Lee
Chan Lee
To support the implementation of genome-based precision medicine, we developed machine learning models that predict the recurrence of patients with gynecologic cancer in using immune checkpoint inhibitors (ICI) based on clinical and pathologic characteristics, including Lynch syndrome-related screening markers such as immunohistochemistry (IHC) and microsatellite instability (MSI) tests. To accomplish our goal, we reviewed the patient demographics, clinical data, and pathological results from their medical records. Then we identified seven potential characteristics (four MMR IHC [MLH1, MSH2, MSH6, and PMS2], MSI, Age 60, and tumor size). Following that, predictive models were built based on these variables using six machine learning algorithms: logistic regression (LR), support vector machine (SVM), naive Bayes (NB), random forest (RF), gradient boosting (GB), and extreme gradient boosting (EGB) (XGBoost). The experimental results showed that the RF-based model performed best at predicting gynecologic cancer recurrence, with AUCs of 0.818 and 0.826 for the 5-fold cross-validation (CV) and 5-fold CV with 10 repetitions, respectively. This study provides novel and baseline results about predicting the recurrence of gynecologic cancer in patients using ICI by using machine learning methods based on Lynch syndrome-related screening markers.

10 February 2020 in Wireless Communications and Mobile Computing
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Sung-Yoon JungSung-Yoon Jung
Sung-Yoon Jung
JLJi-Hwan Lee
Ji-Hwan Lee
WNWonwoo Nam
Wonwoo Nam
Byung Wook KimByung Wook Kim
Byung Wook Kim
Electronic displays and cameras can provide an intuitive, simple communications interface without dependence on additional wireless interfaces or the Internet infrastructure. In this paper, we design a complementary color barcode-based optical camera communication (CCB-OCC) system to provide an easy-to-use communication capability from an electronic display-to-camera (D2C) link. The proposed method encodes information into specially designed color barcodes and transmits it in a format perceptually invisible to humans but detectable by camera-equipped devices. In addition, we propose a new transmission packet design that contains pilot symbols to synchronize symbol packets and estimate the D2C channel link for calibrating captured images caused by irregular differences between the sending color and the receiving color in the D2C link. Experimental results verify the feasibility of the CCB-OCC scheme for short-range communications to offer additional information which shows a new possibility in designing a D2C communication system with robust to environmental change, easy-to-use, and simple implementation.