• Korean Journal of Optics and Photonics
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• v.31 no.6
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• pp.314-320
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• 2020

The optics used in an infrared imaging system has a strong refractive-index change according to temperature, so an autofocus control function is essential for a military infrared imaging system with a wide operating-temperature range. In this study, we design a triple-magnification infrared imaging system, and to compensate for the change in refractive index according to temperature we measure the change in the lens focus according to temperature. The autofocus control function was implemented by using the measured movement amount, and we could obtain an image with satisfactory resolution performance over a wide range of operating temperatures.

• Journal of radiological science and technology
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• v.40 no.1
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• pp.1-6
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• 2017

Visual evaluation of chest radiograph images is the most practical and effective method. This study compared the Body Mass Index, waist circumference, and mAs with chest radiographs of 351 women. The Bureau of Radiological Health method was used to evaluate the image quality of chest X-ray images by anatomical and physical methods. The average age of the subjects was $30.17{\pm}4.73$ and the average waist circumference was $66.91{\pm}4.67cm$. The mean Body Mass Index value was $20.21{\pm}2.23$, the mean value of mAs was $3.04{\pm}0.78$, and the mean value of Bureau of Radiological Health was $79.83{\pm}8.45$. When the Body Mass Index value increased, waist circumference and mAs mean value increased. The mean value of Body Mass Index was statistically significant(p<0.05) in Group 4 compared to Groups 1 and 2, with increasing Body Mass Index. Exposure control of the automatic exposure control system is considered to be well performed according to body thickness or Body Mass Index at the time of chest radiography. As the Body Mass Index increases, the thickness of the body increases and the breast thickness of the woman also increases. Therefore, it is considered that the exposure amount is changed by the automatic exposure control device to affect the image quality.

• Journal of the Korean Society of Visualization
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• v.14 no.1
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• pp.27-32
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• 2016

The reduction of $CO_2$ emissions has been a key target in the Marine Industry since the IMO's Marine Environment Protection Committee published its findings in 2009. The representative emission index is termed as the EEDI (Energy Efficiency Design Index) for the new ships. Among various flow control techniques ever proposed, the air lubrication method is the one of most promising one in terms of practical applicability. The present study examines the basic characteristics of the flat plate test with intention of applying the air lubrication technology to the reduction of the resistance of a ship. Image analysis technique is proposed as a tool to quantify the effectiveness of the air lubrication method.

• KIEE International Transaction on Systems and Control
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• v.12D no.1
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• pp.7-11
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• 2002

In this study, fur the shape-based image retrieval, a method using local differential invariants is proposed. This method calculates the differential invariant feature vector at every feature point extracted by Harris comer point detector. Then through vector quantization using LBG algorithm, all feature vectors are represented by a codebook index. All images are indexed by the histogram of codebook index, and by comparing the histograms the similarity between images is obtained. The proposed method is compared with the existing method by performing experiments for image database including various 1100 trademarks.

• International Journal of Computer Science & Network Security
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• v.23 no.7
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• pp.141-148
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• 2023

During the medical data transmissions, the protection of the patient information is vital. Hence this work proposes a spatial domain watermarking algorithm that enhances the data payload (capacity) while maintaining the authentication and data hiding. The code is distributed at every pixel of the digital image and not only in the regions of non-interest pixels. But the image details are still preserved. The performance of the proposed algorithm is evaluated using several performance measures such as the mean square error (MSE), the mean absolute error (MAE), and the peak signal to noise Ratio (PSNR), the universal image quality index (UIQI) and the structural similarity index (SSIM).

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.311-314
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• 2002

This paper has been studied a Image watermarking using PN coding operation where frequency band. By using wavelet transformation, This gets high frequency place HH2 where image watermark puts. Also this places that PN code and binary image are operated. And then, this paper has designed image watermarking index process and extract process, watermarked image which are to add noise is able to extract watermark.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.1
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• pp.97-110
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• 2021

Vegetation index information is an important figure that is used in many fields such as landscape architecture, urban planning, and environment. Vegetation may vary slightly in vegetation vitality depending on photosynthesis and chlorophyll content. In this study, a range of vegetation worth preserving in the Taehwa River water system was determined, and hyperspectral images of drones were acquired (August, October), and the results were presented through DVI(Normalized Defference Vegetation Index), EVI(Enhanced Vegetation Index), PRI(Photochemical Reflectance Index), ARI (Anthocyanin Reflectance Index) index analysis. In addition, field spectral data and VRS-GPS(Virtual Reference System-GPS) surveys were performed to ensure the quality and location accuracy of the spectral band. As a result of the analysis, NDVI and EVI showed low vegetation vitality in October, -0.165 and -0.085, respectively, and PRI and ARI increased to 0.011 and 7.588 in October, respectively. For general vegetation vitality, it was suggested that NDVI and EVI analysis were effectively performed, and PRI and ARI were thought to be effective in analyzing detailed characteristics of plants by spectral band. It is expected that it can be widely used for park design and landscape information modeling by using drone image information construction and vegetation information.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6273-6278
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• 2015

Objective: This study assessed the association between subjective body image or objective body mass index (BMI) and the risk of daily smoking in Korean adolescents, with a purpose of identifying the most suitable models. Materials and Methods: Using the 2013 9th Korea Youth Risk Behavior Web-based Survey data for 72,435 students, odds ratios were calculated for daily smoking in the past month, according to the subjective body image and calculated BMI using a respective multiple logistic regression model. The combined effect of these two factors was also analyzed by pairing a BMI category with a subjective body image category, using odds ratios for the same event within each sex group. Results: Among the surveyed students, 7.2% of boys and 1.8% of girls were classified as daily smokers. Students who perceived themselves as being very obese tended to be at lower risk of daily smoking (OR=0.61 in boys with 95% CI=0.47 to 0.79; OR=0.66 in women with 95% CI=0.47 to 0.93). In addition, boys within the obese or overweight BMI category showed a lower risk of daily smoking (OR=0.86, 95% CI: 0.77-0.96). Lean BMI was significantly associated with higher odds ratios for daily smoking only in female students (OR=1.24, 95% CI: 1.02-1.52). When pairing these two objective and subjective factors, results suggested that subjective body image has a greater effect on daily smoking than BMI in both boys and girls. Conclusions: In both male and female students, subjective body image had a greater effect on daily smoking than body mass index. A model using the combination of BMI and subjective body image was the best fit in girls, in contrast to the model using subjective body image only best suitable in boys, for the prediction of daily smoking. These results including several factors associated with daily smoking in Korean students, provide useful data for the development and implementation of smoking intervention and cessation programs for adolescents.

• Proceedings of the Korea Society of Design Studies Conference
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• 2005.05a
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• pp.142-143
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• 2005

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.1095-1100
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• 2005

For the establishment of prediction strategies of carcass meat quality grade and for the enhancement of prediction accuracy, sixty six Hanwoo steers were ultrasonically tested at 24 months of age. Ultrasonic meat quality grade were predicted by standard ultrasonic image and decision tree method using ultrasonic meat quality index. From the results of decision tree method using ultrasonic meat quality index, it was found that the marbling score was mainly influenced by the distinctness of rib on ultrasound image. Prediction accuracy of meat quality grade by ultrasonic meat quality index was 86.4%, resulting in 7.6% higher accuracy than that by standard ultrasonic image (78.8%).