• Journal of Platform Technology
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• 제12권1호
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• pp.128-140
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• 2024

딥페이크(Deepfake)란 다양한 인공지능 기술을 활용해 진짜와 같은 가짜를 만드는 영상 합성기술로, 가짜 뉴스 생성, 사기, 악의적인 도용 등에 활용되어 개인과 사회에게 심각한 혼란을 유발시키고 있다. 사회적 문제방지를 위해, 딥페이크로 생성된 이미지를 정교하게 분석하고 탐지하는 방법이 필요하다. 따라서, 본 논문에서는 딥페이크로 생성된 가짜 이미지와 진짜 이미지에서 Saliency 특징을 각각 추출하고 분석하여 합성 후보 영역을 검출하며, 추출된 특징들을 중점으로 학습하여 최종적으로 딥페이크 이미지 탐지 모델을 구축하였다. 제안된 Saliency 기반의 딥페이크 탐지 모델은 합성된 이미지, 동영상 등의 딥페이크 검출 상황에서 공통적으로 사용될 수 있으며, 다양한 비교실험을 통해 본 논문의 제안 방법이 효과적임을 보였다.

• 천문학회보
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• 제46권1호
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• pp.42.1-42.1
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• 2021

In this study, we present a visual explanation of a deep learning solar flare forecast model and its relationship to physical parameters of solar active regions (ARs). For this, we use full-disk magnetograms at 00:00 UT from the Solar and Heliospheric Observatory/Michelson Doppler Imager and the Solar Dynamics Observatory/Helioseismic and Magnetic Imager, physical parameters from the Space-weather HMI Active Region Patch (SHARP), and Geostationary Operational Environmental Satellite X-ray flare data. Our deep learning flare forecast model based on the Convolutional Neural Network (CNN) predicts "Yes" or "No" for the daily occurrence of C-, M-, and X-class flares. We interpret the model using two CNN attribution methods (guided backpropagation and Gradient-weighted Class Activation Mapping [Grad-CAM]) that provide quantitative information on explaining the model. We find that our deep learning flare forecasting model is intimately related to AR physical properties that have also been distinguished in previous studies as holding significant predictive ability. Major results of this study are as follows. First, we successfully apply our deep learning models to the forecast of daily solar flare occurrence with TSS = 0.65, without any preprocessing to extract features from data. Second, using the attribution methods, we find that the polarity inversion line is an important feature for the deep learning flare forecasting model. Third, the ARs with high Grad-CAM values produce more flares than those with low Grad-CAM values. Fourth, nine SHARP parameters such as total unsigned vertical current, total unsigned current helicity, total unsigned flux, and total photospheric magnetic free energy density are well correlated with Grad-CAM values.

• 천문학회보
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• 제41권2호
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• pp.31.2-31.2
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• 2016

We present our study of the correlation between the UV luminosity and the merging activities of nearby galaxies (d < 300 Mpc). Our study uses ~600 UV-selected galaxies with deep optical imaging data, where the UV selection is made using the GALEX Atlas of Galaxies (Gil de Paz et al. 2007) and the updated UV catalog of nearby galaxies (Yu Bai et al. 2015). Deep optical images allow us to classify merger features using visual inspection, and we also estimate unobscured SFR using UV continuum luminosity. The fraction of galaxies with merger features in each UV luminosity bins are obtained to see if how the fraction of galaxies with merging features changes as a function of UV luminosity, Finally, we will show, above what UV luminosity (or SFR), the merging mechanism becomes an important process in enhancing star formation of galaxies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권4호
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• pp.959-979
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• 2024

Rice pest identification is essential in modern agriculture for the health of rice crops. As global rice consumption rises, yields and quality must be maintained. Various methodologies were employed to identify pests, encompassing sensor-based technologies, deep learning, and remote sensing models. Visual inspection by professionals and farmers remains essential, but integrating technology such as satellites, IoT-based sensors, and drones enhances efficiency and accuracy. A computer vision system processes images to detect pests automatically. It gives real-time data for proactive and targeted pest management. With this motive in mind, this research provides a novel farmland fertility algorithm with a deep learning-based automated rice pest detection and classification (FFADL-ARPDC) technique. The FFADL-ARPDC approach classifies rice pests from rice plant images. Before processing, FFADL-ARPDC removes noise and enhances contrast using bilateral filtering (BF). Additionally, rice crop images are processed using the NASNetLarge deep learning architecture to extract image features. The FFA is used for hyperparameter tweaking to optimise the model performance of the NASNetLarge, which aids in enhancing classification performance. Using an Elman recurrent neural network (ERNN), the model accurately categorises 14 types of pests. The FFADL-ARPDC approach is thoroughly evaluated using a benchmark dataset available in the public repository. With an accuracy of 97.58, the FFADL-ARPDC model exceeds existing pest detection methods.

• 한국비블리아학회지
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• 제16권2호
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• pp.157-175
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• 2005

본 논문의 목적은 멀티미디어 내용을 표현하기 위해 제정된 MPEG-7의 비주얼 디스크립터를 설명하고 분석하기 위한 것이다. MPEG-7의 비주얼 디스크립터는 컬러, 모양, 질감, 모션으로 구성되어 있으며 이들 각각의 요소들에 대해 예제 및 응용분야와 더불어서 자세히 설명하고 있다. 마지막으로 본 연구에서는 이들 비주얼 디스크립터에 대한 전반적인 응용분야를 기술하고 있다. 이러한 비주얼 디스크립터들은 다양한 모양의 멀티미디어 내용을 인간의 개입 없이 자동으로 풍부하고 상세하게 표현할 수 있으며 내용 표현의 일관성을 유지하게 함으로써 멀티미디어 검색의 성능을 향상시킬 뿐 아니라 시스템간의 상호운영성을 향상 시킬 수 있을 것으로 기대된다.

• 한국멀티미디어학회논문지
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• 제18권12호
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• pp.1432-1438
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• 2015

We present a methodology to detect moving shadows in video sequences, which is considered as a challenging and critical problem in the most visual surveillance systems since 1980s. While most previous moving shadow detection methods used hand-crafted features such as chromaticity, physical properties, geometry, or combination thereof, our method can automatically learn features to classify whether image segments are shadow or foreground by using a deep learning architecture. Furthermore, applying Markov Random Field enables our system to refine our shadow detection results to improve its performance. Our algorithm is applied to five different challenging datasets of moving shadow detection, and its performance is comparable to that of state-of-the-art approaches.

• 천문학회보
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• 제44권1호
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• pp.52.1-52.1
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• 2019

The Helioseismic and Magnetic Imager (HMI) is the instrument of Solar Dynamics Observatory (SDO) to study the magnetic field and oscillation at the solar surface. The HMI image is not enough to analyze very small magnetic features on solar surface since it has a spatial resolution of one arcsec. Super resolution is a technique that enhances the resolution of a low resolution image. In this study, we use a method for enhancing the solar image resolution using a Deep-learning model which generates a high resolution HMI image from a low resolution HMI image (4 by 4 binning). Deep learning networks try to find the hidden equation between low resolution image and high resolution image from given input and the corresponding output image. In this study, we trained a model based on a very deep residual channel attention networks (RCAN) with HMI images in 2014 and test it with HMI images in 2015. We find that the model achieves high quality results in view of both visual and measures: 31.40 peak signal-to-noise ratio(PSNR), Correlation Coefficient (0.96), Root mean square error (RMSE) is 0.004. This result is much better than the conventional bi-cubic interpolation. We will apply this model to full-resolution SDO/HMI and GST magnetograms.

• Journal of information and communication convergence engineering
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• 제21권4호
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• pp.346-350
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• 2023

Trajectory prediction is an essential element for driving autonomous vehicles, and various trajectory prediction models have emerged with the development of deep learning technology. Convolutional neural network (CNN) is the most commonly used neural network architecture for extracting the features of visual images, and the latest models exhibit high performances. This study was conducted to identify an efficient CNN backbone model among the components of deep learning models for trajectory prediction. We changed the existing CNN backbone network of multiple-trajectory prediction models used as feature extractors to various state-of-the-art CNN models. The experiment was conducted using nuScenes, which is a dataset used for the development of autonomous vehicles. The results of each model were compared using frequently used evaluation metrics for trajectory prediction. Analyzing the impact of the backbone can improve the performance of the trajectory prediction task. Investigating the influence of the backbone on multiple deep learning models can be a future challenge.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2019년도 춘계학술발표대회
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• pp.525-528
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• 2019

Atmospheric particle removal is a challenging task and attacks wide interests in computer vision filed. In this paper, we proposed a single image snow removal framework based on deep residual networks. According to the fact that there are various snow sizes in a snow image, the inception module which consists of different filter kernels was adopted to extract multiple resolution features of the input snow image. Except the traditional mean square error loss, the perceptual loss and total variation loss were employed to generate more clean images. Experimental results on synthetic and realistic snow images indicated that the proposed method achieves superior performance in respect of visual perception and objective evaluation.

• 디지털산업정보학회논문지
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• 제13권4호
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• pp.125-139
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• 2017

In this paper, we developed a framework to detect and predict insider information leakage by collecting and restoring network traffic. For automated behavior analysis, many meta information and behavior information obtained using network traffic collection are used as machine learning features. By these features, we created and learned behavior model, network model and protocol-specific models. In addition, the ensemble model was developed by digitizing and summing the results of various models. We developed a function to present information leakage candidates and view meta information and behavior information from various perspectives using the visual analysis. This supports to rule-based threat detection and machine learning based threat detection. In the future, we plan to make an ensemble model that applies a regression model to the results of the models, and plan to develop a model with deep learning technology.