• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.353-354
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• 2021

In this study, in order to overcome the limitations of the particle size analysis method using a scanner, a microscope, or a laser, and to reduce the cost, a high-quality sampling of micro minerals is performed using an ultra-high-pixel DSLR camera and a MACRO lens. Using this, digital photos taken of standard mineral particles are analyzed to distinguish the size and shape of mineral particles at the level of grain of sand (a few mm ~ 0.063 mm). In addition, various photographing techniques for the production of three-dimensional images of mineral particles were sought, and an attempt was made to produce learning materials and images for mineral classification.

• Journal of Sensor Science and Technology
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• v.26 no.1
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• pp.28-34
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• 2017

An NIR grism Si optical area sensor spectrometer with in-band reference wavelength is designed and fabricated. It is composed of a transmission type diffraction grating (spatial density 300 line/mm), a rectangular N-BK7 prism (apex angle 30 degree), NIR filter(cutoff wavelength 720 nm), an imaging convex lens(focal length 50 mm F1.8) and an IR modified DSLR camera (Canon EOS40D) of Si optical area sensor ($3,888{\times}2,592$ pixels, pixel size $5.710{\mu}m$). "In-band reference wavelength function" is implemented using non-dispersive 0th diffraction order optical beam. The NIR grism spectrometer is tested in a laboratory using a halogen lamp and a Neon lamp. And the spectrometer is used in an astronomy field for obtaining the planet Jupiter NIR spectrum. In-band reference wavelength i.e. un-deviation wavelength is 846 nm, an wavelength resolution is 0.3027 nm/pixel, an wavelength resolving power is 2,794 and an wavelength range is 650~1,000 nm.

• Journal of the Korea Furniture Society
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• v.26 no.4
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• pp.328-333
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• 2015

The museum is a important place to inform the value of various antiquities and relics. The museum, founded in domestic, were increased 90% in 2013 compared to 2006, and total number of including private museums were increased more than three times over the past decade. There are installing a variety of illumination and air-conditioning system, such as the spot lighting of exhibition explanation. But the exhibition explanation should not happen to visual perception disabilities by lighting. According to ICOM (International Council of Museum), it is stipulating that the museum should not to occur glare. However, we confirmed some occurred the glare and it was lack of previous studies about prevention plan. In this study, we verified occurrence of the glare by illumination angles and visitor's eye-level. The luminance values were determined by using DSLR camera and illuminometer. As a result, when illumination angle is 90 degree, the glare did not occurred by the luminance value ratio of over 0.167 regardless of eye-level. By contrast, the angle 30 degree was appeared glare with all level. And this study was compared luminance values that obtained through experiment and surveying.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.1
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• pp.60-67
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• 2022

A study was conducted to analyze the behavioral change of the kerosene flame ultrasonically-atomized under an ultrasonic standing-wave. Combustion region was visualized through DSLR, ICCD camera and the Schlieren photography with high-speed camera. The fuel consumption was measured by a precise scale. As a result, in the case of ultrasonic standing-wave excitation, it was observed that the intensity of OH radical(OH^*) was enhanced and optimal combustion condition was formed around the upper edge of the standing-wave field.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.2
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• pp.30-36
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• 2014

Quality and resolution of camera in mobile device is improved significantly. In this paper, we propose block-based information hide techniques without image distortion for mobile device to solve image degradation in conventional watermarking methods. Information of image is composed with text such as camera maker, model, date, time, etc. Each text is converted to $8{\times}8$ pixel blocks and is added to the bottom of image. Generally image including block based information for image authentication are compressed using JPEG in mobile device. The vertical line value in JPEG header is modified by original size of image sensor. This technique can hide the block based authentication information using general decoder. In the experimental results, JPEG file size is slightly increased within 0.1% for the proposed block based authentication information encoding. Finally proposed methods can be adopted for various embedded systems using medical image, smart phone and DSLR camera.

• Journal of the Korea Society of Computer and Information
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• v.28 no.2
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• pp.19-25
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• 2023

In this paper, we propose a method for improving raw images captured in a low light condition based on deep learning considering the image signal processing. In the case of a smart phone camera, compared to a DSLR camera, the size of a lens or sensor is limited, so the noise increases and the reduces the quality of images in low light conditions. Existing deep learning-based low-light image processing methods create unnatural images in some cases since they do not consider the lens shading effect and white balance, which are major factors in the image signal processing. In this paper, pixel distances from the image center and channel average values are used to consider the lens shading effect and white balance with a deep learning model. Experiments with low-light images taken with a smart phone demonstrate that the proposed method achieves a higher peak signal to noise ratio and structural similarity index measure than the existing method by creating high-quality low-light images.

• Atmosphere
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• v.28 no.3
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• pp.317-324
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• 2018

In this study, we review the ground-based whole-sky camera (WSC), which is developed to continuously capture day and night cloud images using the illumination data from a precision Lightmeter with a high temporal resolution. The WSC is combined with a precision Lightmeter developed in IYA (International Year of Astronomy) for analysis of an artificial light pollution at night and a DSLR camera equipped with a fish-eye lens widely applied in observational astronomy. The WSC is designed to adjust the shutter speed and ISO of the equipped camera according to illumination data in order to stably capture cloud images. And Raspberry Pi is applied to control automatically the related process of taking cloud and sky images every minute under various conditions depending on illumination data from Lightmeter for 24 hours. In addition, it is utilized to post-process and store the cloud images and to upload the data to web page in real time. Finally, we check the technical possibility of the method to observe the cloud distribution (cover, type, height) quantitatively and objectively by the optical system, through analysis of the captured cloud images from the developed device.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.06a
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• pp.130-136
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• 2010

This study estimates and evaluates the parameters to relate spectral intensities of aerial and terrestrial images through spectral analysis of each band. For the experiment, an aerial image covering the headquater of the Kyungpook National University was used and terrestrial images were taken by the Sony DSC-F828 DSLR camera. For finding the spectral correspondence, gray intensity, RGB variance, mean, standard deviation were computed, from which parameters of a linear model between patches of both images were computed and evaluated using check patches.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.1
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• pp.43-49
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• 2016

An experimental study was performed to investigate the combustion characteristics of the liquid hydrocarbon fuel atomized by an ultrasonic oscillator. Configuration of the flame was caught by the DSLR camera, and images were analyzed in detail through a post-processing. Temperature of the flame zone was measured using thermocouple. It is resulted that the flame area is proportional to the mass flow rate of carrier gas as well as the voltage applied to the ultrasonic oscillator. Temperature of the flame zone is measured and analyzed according to variation in the operating condition of the burner, too.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.6
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• pp.53-60
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• 2020

In liquid-fuel spray combustion, an experimental study was conducted to observe the effect of ultrasonic excitation on the ultrasonically-atomized liquid fuel flame by controlling pressure field through an ultrasonic standing wave. Flame of the ultrasonically-atomized kerosene aerosol was visualized by using a high speed camera, DSLR, and Schlieren photography. The amount of fuel consumed was obtained by a precise flow-rate measurement technique during combustion, through which the ratio of carrier gas (air) to fuel mass was able to be obtained, too. As a result, it could be found that the combustion reaction-rate of the liquid-fuel aerosol was increased by applying an ultrasonic standing wave to the secondary flame zone of the flame.