Cheol Hong Kim

ORCID: 0000-0003-1837-6631
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Research Areas
  • Parallel Computing and Optimization Techniques
  • Advanced Data Storage Technologies
  • Interconnection Networks and Systems
  • Embedded Systems Design Techniques
  • Machine Fault Diagnosis Techniques
  • Distributed and Parallel Computing Systems
  • Gear and Bearing Dynamics Analysis
  • Cloud Computing and Resource Management
  • Caching and Content Delivery
  • Fault Detection and Control Systems
  • Music and Audio Processing
  • Low-power high-performance VLSI design
  • 3D IC and TSV technologies
  • Advanced Data Compression Techniques
  • Advanced MIMO Systems Optimization
  • Speech and Audio Processing
  • Green IT and Sustainability
  • Digital Filter Design and Implementation
  • Music Technology and Sound Studies
  • Video Coding and Compression Technologies
  • Network Packet Processing and Optimization
  • Internet of Things and Social Network Interactions
  • Advanced Steganography and Watermarking Techniques
  • Advanced Algorithms and Applications
  • Engineering Diagnostics and Reliability

Soongsil University
2020-2024

Chonnam National University
2011-2020

University of Ulsan
2010-2015

Ulsan University Hospital
2014

Chonnam National University Hospital
2012-2014

Information Technology University
2012-2013

Samsung (South Korea)
1994-2012

Doosan Heavy Industries & Construction (South Korea)
2007

Seoul National University
2004-2006

Hyundai Heavy Industries (South Korea)
1997

Bearing fault diagnosis is imperative for the maintenance, reliability, and durability of rotary machines. It can reduce economical losses by eliminating unexpected downtime in industry due to failure Though widely investigated past couple decades, continued advancement still desirable improve upon existing techniques. Vibration acceleration signals collected from machine bearings exhibit nonstationary behavior variable working conditions multiple severities. In current work, a two-layered...

10.3390/s17122876 article EN cc-by Sensors 2017-12-11

Predicting bearing faults is an essential task in machine health monitoring because bearings are vital components of rotary machines, especially heavy motor machines. Moreover, indicating the degradation level will help factories plan maintenance schedules. With advancements extraction useful information from vibration signals, diagnosis failures by engineers can be gradually replaced automatic detection process. Especially, state-of-the-art methods using deep learning have contributed...

10.3390/app10186385 article EN cc-by Applied Sciences 2020-09-13

This paper proposes a reliable technique for pipeline leak detection using acoustic emission signals. The signal of contains leak-related information. However, the noise in often obscures information, making traditional features, such as count and peaks, less effective. To obtain first, images were obtained from time series signals continuous wavelet transform. (AE images) scalograms that represent time-frequency scales form an image. carried enough information about leak, had high-energy...

10.3390/s22041562 article EN cc-by Sensors 2022-02-17

Bearing fault diagnosis is essential in manufacturing systems to avoid problems such as downtime costs. Convolutional neural network (CNN) models have enabled a new generation of intelligent bearing methods for smart owing their capability extract features 2-dimensional (2D) representations, signals represented the time-frequency domain. Nevertheless, cost and time required collect sufficient training data tend result lack imbalance real scenarios. This inevitable consequence leads high...

10.1109/access.2022.3193244 article EN cc-by IEEE Access 2022-01-01

Condition monitoring is used to track the unavoidable phases of rolling element bearings in an induction motor (IM) ensure reliable operation domestic and industrial machinery. The convolutional neural network (CNN) has been as effective tool recognize classify multiple bearing faults recent times. Due nonlinear nonstationary nature vibration signals, it quite difficult achieve high classification accuracy when directly using original signal input a convolution network. To evaluate fault...

10.3390/electronics10111248 article EN Electronics 2021-05-24

Bearing elements are vital in induction motors; therefore, early fault detection of rolling-element bearings is essential machine health monitoring. With the advantage feature representation techniques time–frequency domain for nonstationary signals and advent convolutional neural networks (CNNs), bearing diagnosis has achieved high accuracy, even at variable rotational speeds. However, required computation memory resources CNN-based methods render it difficult to be compatible with embedded...

10.3390/s20236886 article EN cc-by Sensors 2020-12-02

This paper proposes a Gaussian mixture model-based (GMM) bearing fault band selection (GMM-WBBS) method for signal processing. The proposed benefits reliable feature extraction using frequency oriented model window series. Selecting exclusively harmonics, it eliminates the interference of normal vibrations in lower frequencies, natural and higher contents that prove to be useful only anomaly detection but do not provide any insight into location. features are extracted from time- frequency-...

10.3390/s21196579 article EN cc-by Sensors 2021-10-01

Medical image segmentation is an essential and challenging aspect in computer-aided diagnosis also pattern recognition research. This paper proposes a hybrid method for magnetic resonance (MR) segmentation. We first remove impulsive noise inherent MR images by utilizing vector median filter. Subsequently, Otsu thresholding used as initial coarse that finds the homogeneous regions of input image. Finally, enhanced suppressed fuzzy c-means to partition brain into multiple segments, which...

10.1155/2012/830252 article EN Journal of Biomedicine and Biotechnology 2012-01-01

Bearings prevent damage caused by frictional forces between parts supporting the rotation and they keep rotating shafts in their correct position. However, continuity of work under harsh conditions leads to inevitable bearing failure. Thus, methods for fault diagnosis (FD) that can predict categorize type, as well level degradation, are increasingly necessary factories. Owing advent deep neural networks, especially convolutional networks (CNNs), intelligent FD have achieved significantly...

10.3390/machines9090199 article EN cc-by Machines 2021-09-14

Recent convolutional neural network (CNN) models in image processing can be used as feature-extraction methods to achieve high accuracy well automatic bearing fault diagnosis. The combination of deep learning with appropriate signal representation techniques has proven its efficiency compared traditional algorithms. Vital electrical machines require a strict monitoring system, and the these machines’ systems takes precedence over any other factors. In this paper, we propose new method for...

10.3390/app10207068 article EN cc-by Applied Sciences 2020-10-12

Bearing is one of the most vital components industrial machinery. The failure bearing causes severe problems in Therefore, continuous monitoring for bearings essential rather than regular manual checking, with requirement accuracy prediction and efficiency. This paper proposes a novel intelligent fault condition diagnosis method focusing on computation efficiency, which an important aspect embedded-based device. In proposed method, acoustic emission signals containing health information are...

10.1109/access.2021.3096036 article EN cc-by IEEE Access 2021-01-01

Deep learning (DL) plays a very important role in the fault diagnosis of rotating machinery. To enhance self-learning capacity and improve intelligent accuracy DL for machinery, novel hybrid deep method (NHDLM) based on Extended Convolutional Neural Networks with Wide First-layer Kernels (EWDCNN) long short-term memory (LSTM) is proposed complex environments. First, EWDCNN presented by extending convolution layer WDCNN, which can further automatic feature extraction. The LSTM then changes...

10.3390/s21196614 article EN cc-by Sensors 2021-10-04

Unmanned aerial vehicles (UAVs) and reconfigurable intelligent surfaces (RISs) have garnered considerable research interest in the fields of 5G 6G wireless communication due to their remarkable flexibility cost-effectiveness. However, inherent openness environments renders these technologies vulnerable eavesdropping. This paper presents a penalty-based successive convex approximation algorithm minorize–maximization optimize transmission beamforming vector, RIS UAV–RIS trajectory. The...

10.1016/j.icte.2024.04.008 article EN cc-by ICT Express 2024-04-24

A new method is established to construct the 2-D fault diagnosis representation of multiple bearing defects from 1-D acoustic emission signals. This technique starts by applying envelope analysis extract signal. novel strategy propounded for deployment continuous wavelet transform with damage frequency band information generate defect signature image (DSWI), which describes signal in time-frequency-domain, reduces nonstationary effect signal, shows discriminate pattern visualization...

10.3390/app10248800 article EN cc-by Applied Sciences 2020-12-09

A case study reveals that energy savings do not always translate to longer smartphone battery life and evaluating any plan must be based on consumption, used.

10.1109/mc.2013.293 article EN Computer 2013-08-15

The high-frequency band, crucial for supporting the 5G/6G system, faces challenges of signal obstruction by obstacles. This is attributed to significant path loss resulting from radio straightness and short distance. To address these challenges, there a growing interest in leveraging non-terrestrial networks (NTNs) reconfigurable intelligent surfaces (RISs), utilizing high-altitude satellites as base stations or terminals. Within three-dimensional NTN vulnerability wireless signals...

10.1016/j.icte.2024.04.003 article EN cc-by ICT Express 2024-04-10

Recently, 3D integration has been regarded as one of the most promising techniques due to its abilities reducing global wire lengths and lowering power consumption. However, integrated processors inevitably cause higher density lower thermal conductivity, since closer proximity heat generating dies makes existing hotspots more severe. Without an efficient cooling method inside package, should suffer severe performance degradation by dynamic management well reliability problems. In this...

10.1109/iccd.2009.5413115 article EN 2009-10-01

Gearbox fault diagnosis based on the analysis of vibration signals has been a major research topic for few decades due to advantages characteristics. Such characteristics are used early detection guarantee enhanced safety complex systems and their cost-effective operation. There exist many models that have developed classifying various types in gearboxes. However, classification results conventional degrade when they applied gearbox with multi-level tooth cut gear (MTCG) faults operating...

10.3390/s21010018 article EN cc-by Sensors 2020-12-22

This study aims at characterizing crack types for reinforced concrete beams through the use of acoustic emission burst (AEB) features. The includes developing a solid assessment indicator (CAI) accompanied by detection method using k-nearest neighbor (k-NN) algorithm that can successfully distinguish among normal condition, micro-cracks, and macro-cracks (fractures) beam test specimens. Reinforced (RC) undergo three-point bending test, from which (AE) signals are recorded further processing....

10.3390/app10217918 article EN cc-by Applied Sciences 2020-11-08

In this paper, an adaptive Takagi–Sugeno (T–S) fuzzy sliding mode extended autoregressive exogenous input (ARX)–Laguerre proportional integral (PI) observer is proposed. The proposed T–S extended-state ARX–Laguerre PI adaptively improves the reliability, robustness, estimation accuracy, and convergence of fault detection, estimation, identification. For fault-tolerant control in presence uncertainties unknown conditions, technique introduced. surface slope gain significant to improve...

10.3390/en12071281 article EN cc-by Energies 2019-04-03

In this paper, we propose a three-stage lightweight framework for centrifugal pump fault diagnosis. First, the vibration signatures are fast transformed using Walsh transform, and spectra obtained. To overcome hefty noise produced by macro-structural vibration, proposed method selects characteristic coefficients of spectrum. second stage, statistical features in time spectrum domain extracted from selected transform. These raw result hybrid high-dimensional space. Not all these help...

10.1109/access.2021.3124903 article EN cc-by IEEE Access 2021-01-01

In this paper, the short-term load forecast is conducted by utilizing SARIMA model and Holt-Winters including classification use of k-NN algorithm. With embodiment a procedure, it could be possible to provide more accurate data. After using 1-year training set test set, was performed through two models. Although differences in results were minor, measuring their MAPE, shown have better performance forecasting.

10.1109/isco.2013.6481140 article EN 2013-01-01

In this paper, we propose a highly reliable state monitoring system for induction motors. The proposed utilizes vibration signals to analyze characteristics of the motor and extract features classifying abnormal states from normal ones. To faulty healthy signals, first convert one-dimension into two-dimension gray images utilize relationship between each element its neighboring elements, calculate number significant pixels in these converted images. We then use multiclass support vector...

10.1080/13614568.2013.832407 article EN New Review of Hypermedia and Multimedia 2013-10-11
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