• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.460-460
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• 2023

최근 범 지구적인 기후변화로 인해 집중호우가 빈번히 발생하고 침수피해가 증가하고 있다. 이에 따른 침수 피해 위험이 큰 지하상가, 지하 주차장, 반지하 주택 등의 침수 발생이 잦아지며 인명 및 재산 피해 발생이 커지고 있다. 이러한 지역은 인근 하수관로의 수위에 따라 침수 영향을 크게 받게 된다. 이에 따른 강우·유출 관계는 침수피해에 대해 대처하기 위해 시공간적 강우 특성이 반영된 하수관로 수위 예측이 중요하다고 판단된다. 이에 본 연구에서 수위 자료는 서울시 하수관로 수위 현황 자료를 활용하였으며, 강수량 자료는 서울 내 서초구 일대의 강수량 자료를 활용하여 연구를 진행하였다. 대상 지역은 저지대에 위치해 침수가 잦은 서초구 서초동으로 선정하였으며, 분석에 사용된 기간은 2012년부터 2021년까지의 수위 자료를 화용하여 이를 바탕으로 순환 신경망인 RNN의 일종이며, 다른 모델의 구조와 비교하여 더욱 간단하고 효율적인 ESN(Echo State Network) 알고리즘을 사용하여 수위 예측을 진행하였다. 분석을 위해 대상 지역의 강수 사상이 발생하여 하수관로의 수위의 변동이 큰 기간을 선정하여 분석을 실시하였다. 2012년부터 2018년까지의 자료를 학습(training) 자료로 활용하였으며, 모형의 검증 위해 통계분석을 실시하여 검증하였다.

• Journal of Information Technology Services
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• v.22 no.6
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• pp.71-86
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• 2023

The rapid change in industry and the technological gap give rise to social demand for upskilling and reskilling and spread of alternative education. Against this backdrop, digital certification and career management tools can be used to manage various types of learning activities comprehensively. Digital badges provide various kinds of history information related to individual learning, and the reliability and transparency of the issued information can be strengthened by applying blockchain technology. There have been various discussions about digital badges for a long time, but due to the lack of standards to support the issuance and distribution of digital badges, they have been partially used in some areas. However, interest in digital badges is increasing due to the development of related technologies, establishment of standards, paradigm changes in higher education, and government policies related to nurturing digital talent. This paper deals with the use of digital badges for efficient and transparent learning management and career management in an online learning environment. The researcher analyzes the technical characteristics and use cases of digital badges, and proposes a plan for use in online higher education based on them.

• Wind and Structures
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• v.38 no.1
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• pp.75-91
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• 2024

Reliable wind signal reconstruction can be beneficial to the operational safety of long-span bridges. Non-Gaussian characteristics of wind signals make the reconstruction process challenging. In this paper, non-Gaussian wind signals are converted into a combined prediction of two kinds of features, actual wind speeds and wind angles of attack. First, two decomposition techniques, empirical mode decomposition (EMD) and variational mode decomposition (VMD), are introduced to decompose wind signals into intrinsic mode functions (IMFs) to reduce the randomness of wind signals. Their principles and applicability are also discussed. Then, four artificial intelligence (AI) algorithms are utilized for wind signal reconstruction by combining the particle swarm optimization (PSO) algorithm with back propagation neural network (BPNN), support vector regression (SVR), long short-term memory (LSTM) and bidirectional long short-term memory (Bi-LSTM), respectively. Measured wind signals from a bridge site in a deep-cutting gorge are taken as experimental subjects. The results showed that the reconstruction error of high-frequency components of EMD is too large. On the contrary, VMD fully extracts the multiscale rules of the signal, reduces the component complexity. The combination of VMD-PSO-Bi-LSTM is demonstrated to be the most effective among all hybrid models.

• Korean Journal of Radiology
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• v.25 no.6
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• pp.518-539
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• 2024

Coronary computed tomography angiography (CCTA) has emerged as a pivotal tool for diagnosing and risk-stratifying patients with suspected coronary artery disease (CAD). Recent advancements in image analysis and artificial intelligence (AI) techniques have enabled the comprehensive quantitative analysis of coronary atherosclerosis. Fully quantitative assessments of coronary stenosis and lumen attenuation have improved the accuracy of assessing stenosis severity and predicting hemodynamically significant lesions. In addition to stenosis evaluation, quantitative plaque analysis plays a crucial role in predicting and monitoring CAD progression. Studies have demonstrated that the quantitative assessment of plaque subtypes based on CT attenuation provides a nuanced understanding of plaque characteristics and their association with cardiovascular events. Quantitative analysis of serial CCTA scans offers a unique perspective on the impact of medical therapies on plaque modification. However, challenges such as time-intensive analyses and variability in software platforms still need to be addressed for broader clinical implementation. The paradigm of CCTA has shifted towards comprehensive quantitative plaque analysis facilitated by technological advancements. As these methods continue to evolve, their integration into routine clinical practice has the potential to enhance risk assessment and guide individualized patient management. This article reviews the evolving landscape of quantitative plaque analysis in CCTA and explores its applications and limitations.

• Journal of Information Technology Services
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• v.23 no.3
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• pp.91-101
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• 2024

Based on the analysis of 174 Young Startups Project Papers from university students majoring in entrepreneurship, this study aimed to identify the thoughts and characteristics of prospective entrepreneurs and derive their main agendas. Detailed information was collected on their preparation and ambitions for entrepreneurship, market research in their fields of interest, analysis of potential target users, requirements, and team management. We refined, categorized, and interpreted 84,818 words across 396 digital pages on LMS, and visualized using word clouds program. Additionally, interviews about peer learning were conducted by Zoom. The analysis revealed unique differences in students' perspectives on entrepreneurship based on their major, academic year, and gender. Also we could find that they actively utilize AI tech with a strong spirit of challenge in the startups. Interestingly, they emphasized horizontal communication and collaboration capabilities to improve productivity. This suggests the need to consider diversity in the design of entrepreneurship incubating content and programs for generation Z technically and academically.

• The Journal of the Convergence on Culture Technology
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• v.10 no.4
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• pp.663-668
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• 2024

This paper applies statistical analysis methods in the time domain to the fault diagnosis of wafer transfer robots, and proposes a methodology to discern the critical characteristics of vibration and torque signals. Subsequently, principal component analysis (PCA) is applied to diminish the data's dimensionality, followed by the development of a fault diagnosis algorithm utilizing Euclidean distance and Hotelling's T-square statistics. The algorithm establishes decision boundaries to categorize failure states based on the observed data. Our findings indicate that data classification incorporating velocity parameters enhances diagnostic accuracy. This approach serves to enhance the precision and efficacy of fault diagnosis.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.262-273
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• 2024

We provide a detailed analysis of the data processing and model training process for vulnerability classification using Transformer-based language models, especially sentence text-to-text transformers (ST5)-XXL and XLNet. The main purpose of this study is to compare the performance of the two models, identify the strengths and weaknesses of each, and determine the optimal learning rate to increase the efficiency and stability of model training. We performed data preprocessing, constructed and trained models, and evaluated performance based on data sets with various characteristics. We confirmed that the XLNet model showed excellent performance at learning rates of 1e-05 and 1e-04 and had a significantly lower loss value than the ST5-XXL model. This indicates that XLNet is more efficient for learning. Additionally, we confirmed in our study that learning rate has a significant impact on model performance. The results of the study highlight the usefulness of ST5-XXL and XLNet models in the task of classifying security vulnerabilities and highlight the importance of setting an appropriate learning rate. Future research should include more comprehensive analyzes using diverse data sets and additional models.

• Food Science of Animal Resources
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• v.34 no.5
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• pp.582-590
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• 2014

The effect of mugwort extract (ME) and vitamin C (VC), added individually or in combination, on color, lipid oxidation, and sensory characteristics of chicken nuggets stored for 12 d was investigated. Eight treatments of chicken nuggets contained the following: Control (no antioxidant added), VC (0.05% VC), ME 0.05 (0.05% ME), ME 0.1 (0.1% ME), ME 0.2 (0.2% ME), VC+ME 0.05 (0.05% VC + 0.05% ME) and VC+ME 0.1 (0.05% VC + 0.1% ME), VC+ME 0.2 (0.05% VC + 0.2% ME). Results showed that the mixture of 0.05% VC and 0.2% ME was most effective for delaying lipid oxidation (thiobarbituric acid reactive substances, conjugated dienies, and peroxide formation) when compared to the control or ME alone added. The color values of all treatments were significantly affected by adding ME. Additionally, the total color difference (${\Delta}E$), chroma ($C^*$), and hue angle ($H^{\circ}$) values of all treatments, except for VC, were lower than those of the control as the amount of ME increased. The sensory characteristics (flavor, odor, and overall acceptability) did not differ significantly in any of the chicken nugget samples, whereas storage time had a significant effect. The results suggest that the possibility of utilizing chicken nuggets with a mixture of mugwort extract and vitamin C for the increase of shelf-life and quality.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.10
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• pp.23-28
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• 2010

In this paper, we investigated the polarization effects on the electrical and structural characteristics of AlGaN/GaN HEMT. Both the Al mole-fraction and the barrier thickness of AlGaN, which determine the profiles of a two-dimensional electron gas, were simulated to obtain the optimum HEMT structure affecting the polarization effect. As a results, we found that the amount of bound sheet charges was increased by 16% and the maximum drain current density ($I_D$,max) was increased by more than 37%, while AI mole fractions are changed from 0.3 to 0.4. We also observed a 37% improvement in maximum drain current density ($I_D$,max) by increasing AIGaN layer thickness from 17 to 38 nm. However when AlGaN layer thickness reached the critical thickness, DC characteristics were dramatically lowered due to 'bulk' relaxation in AlGaN layer.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.2 s.121
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• pp.13-24
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• 2007

This study aims to investigate the characteristics of Lee Kyo-Won's landscape architecture and add to the literature in this field. Also, the current status of and issues in landscape design will be dealt with through the lens of the individual landscape architect's worts. By adopting a critical analysis, this study will look closely into the background of his career and ideas regarding landscape design. The inherent nature of his coherent style in landscape design will be listed as follows: total design, design-build systems, experimentation with new kinds of plants and materials, and the pursuit of minimalism. His design domain covers various elements such as paving, street lamps, and clock towers, among others. He was often involved in managing outdoor sculpture and he also provided the total packaging of the design-build systems for most of his landscape projects. These are the main reasons why his landscape works can maintain their high end quality; through his craftsmanship, a fine quality of detail was achieved in his landscape design. This tell us the possible options that can be adopted such as landscape architectural design management or landscape architectural turn-key systems, which differ from the prevailing dual system between design and construction. However, his own particular system can not be replicated in ordinary situations because contemporary practices require us to coordinate the various stakeholders concerned in the decision-making process of the design. In general, it is fair to say that we can give him the credit for enhancing the status of landscape design as an independent, specialized field.