Yoon Jae Lee

Mr. Yoon Jae Lee

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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18 December 2021 in Sensors
Verified
Journal Article
Open access
PDF file
YLYoon Jae Lee
Yoon Jae Lee
MJMinho Jo
Minho Jo
Gyoujin ChoGyoujin Cho
Gyoujin Cho
CJChangbeom Joo
Changbeom Joo
Changwoo LeeChangwoo Lee
Changwoo Lee
Gravure printing, which is a roll-to-roll printed electronics system suitable for high-speed patterning of functional layers have advantages of being applied to flexible webs in large areas. As each of the printing procedure from inking to doctoring followed by ink transferring and setting influences the quality of the pattern geometry, it is necessary to detect and diagnose factors causing the printing defects beforehand. Data acquisition with three triaxial acceleration sensors for fault diagnosis of four major defects such as doctor blade tilting fault was obtained. To improve the diagnosis performances, optimal sensor selection with Sensor Data Efficiency Evaluation, sensitivity evaluation for axis selection with Directional Nature of Fault and feature variable optimization with Feature Combination Matrix method was applied on the raw data to form a Smart Data. Each phase carried out on the raw data progressively enhanced the diagnosis results in contents of accuracy, positive predictive value, diagnosis processing time, and data capacity. In the case of doctor blade tilting fault, the diagnosis accuracy increased from 48% to 97% with decreasing processing time of 3640 s to 16 s and the data capacity of 100 Mb to 5 Mb depending on the input data between raw data and Smart Data.

12 June 2024 in Machines
Verified
Journal Article
Open access
PDF file
SLSangbin Lee
Sangbin Lee
YLYoon Jae Lee
Yoon Jae Lee
BPByeonghui Park
Byeonghui Park
Changwoo LeeChangwoo Lee
Changwoo Lee
Scarfing is a type of flame treatment used to improve the quality of metal generated during steelmaking. It employs the principles of gas cutting to remove impurities and defects. Due to the high-temperature conditions and the need for uniform metal treatment, mechanical scarfing performed via a frame is preferred over manual hand scarfing. To achieve stable mechanical scarfing, a properly designed frame is essential. Generally, while using more material can create stable equipment, it also increases costs. Therefore, this study proposed a design method that selects an acceleration profile to minimize the shock on the frame during scarfing equipment operation while using a multi-objective genetic algorithm to minimize weight and maximize rigidity. Because modifying existing scarfing equipment based on the optimization results would incur additional costs and time, pre-optimizing through simulation before equipment fabrication is crucial. Optimization was achieved via the dimensional optimization of the existing frame equipment. As a result, the weight of each part and the deformation decreased by an average of 17.05 kg and 3.93%, respectively.

19 April 2024 in Polymers
Verified
Journal Article
Open access
PDF file
YLYoon Jae Lee
Yoon Jae Lee
JYJunyoung Yun
Junyoung Yun
SLSangbin Lee
Sangbin Lee
Changwoo LeeChangwoo Lee
Changwoo Lee
Roll-to-roll (R2R) manufacturing depends on a system’s capability to deposit high-quality coatings with precise thickness, width, and uniformity. Therefore, consistent maintenance requires the immediate and accurate detection of coating defects. This study proposes a primary color selection (PCS) method to detect edge defects in R2R systems. This method addresses challenges associated with training data demands, complexity, and defect adaptability through a vision data-centric approach, ensuring precise edge coating defect detection. Using color information, high accuracy was achieved while minimizing data capacity requirements and processing time. Precise edge detection was facilitated by accurately distinguishing coated and noncoated regions by selecting the primary color channel based on color variability. The PCS method achieved superior accuracy (95.8%), outperforming the traditional weighted sum method (78.3%). This method is suitable for real-time detection in manufacturing systems and mitigates edge coating defects, thus facilitating quality control and production optimization.

3 March 2022 in Sensors
Verified
Journal Article
Open access
PDF file
BPByeonghui Park
Byeonghui Park
YLYoon Jae Lee
Yoon Jae Lee
MYMyeonghwan Yeo
Myeonghwan Yeo
HLHaemi Lee
Haemi Lee
CJChangbeom Joo
Changbeom Joo
Changwoo LeeChangwoo Lee
Changwoo Lee
Fault diagnosis systems are used to improve the productivity and reduce the costs of the manufacturing process. However, the feature variables in existing systems are extracted based on the classification performance of the final model, thereby limiting their applications to models with different conditions. This paper proposes an algorithm to improve the characteristics of feature variables by considering the cutting conditions. Regardless of the frequency band, the noise of the measurement data was reduced through an oversampling method, setting a window length through a cutter sampling frequency, and improving its sensitivity to shock signal. An experiment was subsequently performed to confirm the performance of the model. Using normal and wear tools on AI7075 and SM45C, the diagnosis accuracies were 97.1% and 95.6%, respectively, with a reduction of 85% and 83%, respectively, in the time required to develop a diagnosis model. Therefore, the proposed algorithm reduced the model computation time and developed a model with high accuracy by enhancing the characteristics of the feature variable. The results of this study can contribute significantly to the establishment of a high-precision monitoring system for various processing processes.

13 September 2023 in Sensors
Verified
Journal Article
Open access
PDF file
HLHaemi Lee
Haemi Lee
YLYoon Jae Lee
Yoon Jae Lee
MJMinho Jo
Minho Jo
SNSang-Hoon Nam
Sang-Hoon Nam
Jeongdai JoJeongdai Jo
Jeongdai Jo
Changwoo LeeChangwoo Lee
Changwoo Lee
Roll-to-roll manufacturing systems have been widely adopted for their cost-effectiveness, eco-friendliness, and mass-production capabilities, utilizing thin and flexible substrates. However, in these systems, defects in the rotating components such as the rollers and bearings can result in severe defects in the functional layers. Therefore, the development of an intelligent diagnostic model is crucial for effectively identifying these rotating component defects. In this study, a quantitative feature-selection method, feature partial density, to develop high-efficiency diagnostic models was proposed. The feature combinations extracted from the measured signals were evaluated based on the partial density, which is the density of the remaining data excluding the highest class in overlapping regions and the Mahalanobis distance by class to assess the classification performance of the models. The validity of the proposed algorithm was verified through the construction of ranked model groups and comparison with existing feature-selection methods. The high-ranking group selected by the algorithm outperformed the other groups in terms of training time, accuracy, and positive predictive value. Moreover, the top feature combination demonstrated superior performance across all indicators compared to existing methods.

1 January 2020
Verified
Conference Paper
Closed access
LKLiam Kelly
Liam Kelly
YLYoon Jae Lee
Yoon Jae Lee
HPHaekwang Park
Haekwang Park
It has been shown that a loudspeaker coupled to a long narrow pipe through which sound is radiated through a series of small spaced apertures can have narrow directivity. This paper describes a process by which this concept is practically applied for use in a soundbar for delivering sound to a listener indirectly by reflection from room surfaces. A model was developed and used to guide the process which revealed various sound quality issues for a basic design. With modifications a successful approach with narrow directional sound of an acceptable quality was found. Its architecture and performance are reported.