• 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.

• IEIE Transactions on Smart Processing and Computing
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• 제2권5호
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• pp.255-265
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• 2013

3DTV is expected to be a promising next-generation broadcasting service. On the other hand, the visual discomfort/fatigue problems caused by viewing 3D videos have become an important issue. This paper proposes a perceptual quality assessment metric for a stereoscopic video (SV-PQAM). To model the SV-PQAM, this paper presents the following features: temporal variance, disparity variation in intra-frames, disparity variation in inter-frames and disparity distribution of frame boundary areas, which affect the human perception of depth and visual discomfort for stereoscopic views. The four features were combined into the SV-PQAM, which then becomes a no-reference stereoscopic video quality perception model, as an objective quality assessment metric. The proposed SV-PQAM does not require a depth map but instead uses the disparity information by a simple estimation. The model parameters were estimated based on linear regression from the mean score opinion values obtained from the subjective perception quality assessments. The experimental results showed that the proposed SV-PQAM exhibits high consistency with subjective perception quality assessment results in terms of the Pearson correlation coefficient value of 0.808, and the prediction performance exhibited good consistency with a zero outlier ratio value.

• 대한인간공학회지
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• 제23권3호
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• pp.89-99
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• 2004

A comprehensive psychophysical scaling system, multiple-modality magnitude estimation system (MMES) has been designed to measure subjective multidimensional human perception. Unlike paper-based magnitude estimation systems, the MMES has an additional auditory peripheral cue that varies with corresponding visual magnitude. As the simplest, purely psychological case, bimodal divided-attention conditions were simulated to establish the superiority of the MMES. Subjects were given brief presentations of pairs of simultaneous stimuli consisting of visual line-lengths and auditory white-noise levels. In the visual or auditory focused-attention conditions, only the line-lengths or the noise levels perceived should be reported respectively. On the other hand, in the divided-attention conditions, both the line-lengths and the noise levels should be reported. There were no significant differences among the different attention conditions. Human performance was better when the proportion of magnitude in stimulus pairs were identically presented. The additional auditory cues in the MMES improved the correlations between the magnitude of stimuli and MMES values in the divided-attention conditions.

• 한국안광학회지
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• 제10권3호
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• pp.221-228
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• 2005

현재 국내에서 유통되고 있는 국내외 렌즈제품들을 대상으로 굴절력과 중심부 두께의 측정을 통해 제품간의 차이를 분석하였다. 국내 제품들은 해외제품에 버금갈 정도로 제작되었지만 허용기준에 맞지 않는 경우가 있었으며, 또 통일 제품들에서도 차이를 줄일 필요가 있다. 국내제품들이 해외 제품들에 비해 더 경쟁력을 가지기 위해서는 전문인력의 육성, 엄격한 품질검사, 공정관리, 규격의 표준화가 필요하다.

• 한국도로학회논문집
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• 제18권4호
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• pp.47-53
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• 2016

PURPOSES : The objective of this study was to evaluate the results of the dynamic immersion test (DIT) through digital image analysis (DIA). METHODS : The asphalt binder retained post DIT was inspected visually by more than three investigators. However, because visual observations can be subjective, depending on the inspector's skills and knowledge, DIA was also performed. The threshold value for the DIA was determined by a mesh analysis, in which the digital image to be analyzed is divided into very small meshes. In addition, the bitumen bond strength (BBS) test was also performed to the compare the visual results with the mechanical values. RESULTS AND CONCLUSIONS : Depending on the materials used, various methods can be used to predict the behavior of retained asphalt. However, the increasing ratio in the trend of retained asphalt shows different behaviors among the evaluation methods. In this study, the results of the visual observations were significantly different from those of the DIA, the mesh analysis, and the BBS tests. Thus, DIA is an appropriate method for evaluating the results of the DIT. However, in order to use this technique in the field, it is necessary to determine a more reasonable threshold value by performing DIA on various materials.

• 한국콘텐츠학회논문지
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• 제17권8호
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• pp.110-120
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• 2017

한자의 부수는 한자의 특성을 계승하고 독특한 문화 정보를 내포하고 있다. 특히 한자 부수의 형식미는 시각디자인에 있어서 한자 형상의 잠재력을 발휘하는데 중요한 역할을 하며, 현대 디자인에 다양하게 활용할 수 있다. 본 연구에서는 중국현대 포스터 디자인에서 한자 부수의 활용을 분석함으로써 한자 부수의 형태적, 표현적, 전통적 특징을 파악하고, 이 특징들을 어떻게 계승 발전시킬 것인지를 탐구해본다. 이러한 연구를 통해 한자부수가 가진 시각언어로서의 문화적 가치를 재인식하는 것에 목적을 둔다. 연구는 문헌고찰을 통해 한자의 역사와 구조, 부수의 역사, 기능, 분류, 의미에 대해 각각 정리하였다. 부수를 사용한 포스터의 사례분석을 통하여 포스터에서 부수의 역할 및 잠재된 시각적 표현 방법과 객관적 법칙에 대해 총괄하였다.

• 한국환경교육학회지:환경교육
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• 제16권2호
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• pp.65-73
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• 2003

This study has an aim to construct a reference frame to analyze the appropriateness of environmental education(EE) materials of elementary schools, and to search the basic direction of the scheme for analysis. In addition, this study has an aim to induce what the results of this analysis suggests for the development and reconstruction of EE materials. It was analyzed how truly EE materials reflected contents selected as an analysis scheme, after grasping practical use and features of textbooks, audio-visual materials, and a web-site that are typical materials in EE of elementary schools. The results in textbook analysis were that there were a human-centered environmentalism in the EE unit ("Environmentally Sound National Development", 5th Grade) of Social Studies. The result in analysis of audio-visual materials "Environmental Warrior, Zentaforce" of EBS, were that there are unhealthy environmentalism in that material. In other words, technology itself is considered as a almighty means to solve environmental problems. Finally, the result in web-site analysis were that the "Environmental Class" of Ministry of Environment did not have sound environmentalism. The above result of study shows us that the most important thing in developing and using the environmental education materials is to have sound environmental values and EE perspective, to evaluate EE material with various point of view, to judge its result, and to use it.

• 센서학회지
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• 제21권3호
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• pp.211-216
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• 2012

Fires are the most common disaster and early fire detection is of great importance to minimize the consequent damage. Simple sensors including smoke detectors are widely used for the purpose but they are able to sense fires only at close proximity. Recently, due to the rapid advances of relevant technologies, vision-based fire sensing has attracted growing attention. In this paper, a novel visual sensing technique to automatically detect fire is presented. The proposed technique consists of multiple steps of image processing: pixel-level, block-level, and frame level. At the first step, fire flame pixel candidates are selected based on their color values in YIQ space from the image of a camera which is installed as a vision sensor at a fire scene. At the second step, the dynamic parts of flames are extracted by comparing two consecutive images. These parts are then represented in regularly divided image blocks to reduce pixel-level detection error and simplify following processing. Finally, the temporal change of the detected blocks is analyzed to confirm the spread of fire. The proposed technique was tested using real fire images and it worked quite reliably.

• 한국안광학회지
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• 제13권2호
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• pp.37-41
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• 2008

목적: 이 증례의 목적은 흔치 않은 회선수직사위에 대한 프리즘 처방에 관한 것이다. 방법: 처방 프리즘은 사위도, 융합력, 조절기능 검사등과 같은 양안시 평가에서 수직이향운동의 파괴점의 중앙점으로 하였다. 결과: 수직 프리즘의 처방으로 비록 증상이 따르지 않은 수평사위는 변화가 있었으나 눈의 피로, 두통, 복시 등과 같은 증상은 개선 되었다. 그리고 회선사위는 프리즘 교정으로 나타나지 않았다. 결론: 이 사례의 프리즘 처방은 회선수직사위의 증상 완화에 유용하였다.

• International Journal of Contents
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• 제11권3호
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• pp.47-53
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• 2015

Visual object tracking is a fundamental problem in the field of computer vision, as it needs a proper model to account for drastic appearance changes that are caused by shape, textural, and illumination variations. In this paper, we propose a feature-based visual-object-tracking method with a sparse representation. Generally, most appearance-based models use the gray-scale pixel values of the input image, but this might be insufficient for a description of the target object under a variety of conditions. To obtain the proper information regarding the target object, the following combination of features has been exploited as a corresponding representation: First, the features of the target templates are extracted by using the HOG (histogram of gradient) and LBPs (local binary patterns); secondly, a feature-based sparsity is attained by solving the minimization problems, whereby the target object is represented by the selection of the minimum reconstruction error. The strengths of both features are exploited to enhance the overall performance of the tracker; furthermore, the proposed method is integrated with the particle-filter framework and achieves a promising result in terms of challenging tracking videos.