• Korean Journal of Geomatics
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• v.3 no.1
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• pp.33-41
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• 2003

Every year, several typhoons hit the Korean peninsula and cause severe damage. For the prevention and accurate estimation of these damages, real time or almost real time flood information is essential. Because of weather conditions, images taken by optic sensors or LIDAR are sometimes not appropriate for an accurate estimation of water areas during typhoon. In this case SAR (Synthetic Aperture Radar) images which are independent of weather condition can be useful for the estimation of flood areas. To get detailed information about floods from satellite imagery, accurate classification of water areas is the most important step. A commonly- and widely-used classification methods is the ML(Maximum Likelihood) method which assumes that the distribution of brightness values of the images follows a Gaussian distribution. The distribution of brightness values of the SAR image, however, usually does not follow a Gaussian distribution. For this reason, in this study the ANN (Artificial Neural Networks) method independent of the statistical characteristics of images is applied to the SAR imagery. RADARS A TSAR images are primarily used for extraction of water areas, and DEM (Digital Elevation Model) is used as supplementary data to evaluate the ground undulation effect. Water areas are also extracted from KOMPSAT image achieved by optic sensors for comparison purpose. Both ANN and ML methods are applied to flat and mountainous areas to extract water areas. The estimated areas from satellite imagery are compared with those of manually extracted results. As a result, the ANN classifier performs better than the ML method when only the SAR image was used as input data, except for mountainous areas. When DEM was used as supplementary data for classification of SAR images, there was a 5.64% accuracy improvement for mountainous area, and a similar result of 0.24% accuracy improvement for flat areas using artificial neural networks.

• The Korean Journal of Pain
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• v.28 no.2
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• pp.105-108
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• 2015

Background: The most definitive diagnosis of neck pain caused by facet joints can be obtained through cervical medial branch blocks (CMBBs). However, intravascular injections need to be carefully monitored, as they can increase the risk of false-negative blocks when diagnosing cervical facet joint syndrome. In addition, intravascular injections can cause neurologic deficits such as spinal infarction or cerebral infarction. Digital subtraction angiography (DSA) is a radiological technique that can be used to clearly visualize the blood vessels from surrounding bones or dense soft tissues. The purpose of this study was to compare the rate of detection of intravascular injections during CMBBs using DSA and static images obtained through conventional fluoroscopy. Methods: Seventy-two patients were included, and a total of 178 CMBBs were performed. The respective incidences of intravascular injections during CMBBs using DSA and static images from conventional fluoroscopy were measured. Results: A total of 178 CMBBs were performed on 72 patients. All cases of intravascular injections evidenced by the static images were detected by the DSAs. The detection rate of intravascular injections was higher from DSA images than from static images (10.7% vs. 1.7%, P < 0.001). Conclusions: According to these findings, the use of DSA can improve the detection rate of intravascular injections during CMBBs. The use of DSA may therefore lead to an increase in the diagnostic and therapeutic value of CMBBs. In addition, it can decrease the incidence of potential side effects during CMBBs.

• Imaging Science in Dentistry
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• v.48 no.2
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• pp.111-119
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• 2018

Purpose: This study was conducted to evaluate the accuracy of linear measurements of 3-dimensional (3D) images generated by cone-beam computed tomography (CBCT) and facial scanning systems, and to assess the effect of scanning parameters, such as CBCT exposure settings, on image quality. Materials and Methods: CBCT and facial scanning images of an anthropomorphic phantom showing 13 soft-tissue anatomical landmarks were used in the study. The distances between the anatomical landmarks on the phantom were measured to obtain a reference for evaluating the accuracy of the 3D facial soft-tissue images. The distances between the 3D image landmarks were measured using a 3D distance measurement tool. The effect of scanning parameters on CBCT image quality was evaluated by visually comparing images acquired under different exposure conditions, but at a constant threshold. Results: Comparison of the repeated direct phantom and image-based measurements revealed good reproducibility. There were no significant differences between the direct phantom and image-based measurements of the CBCT surface volume-rendered images. Five of the 15 measurements of the 3D facial scans were found to be significantly different from their corresponding direct phantom measurements(P<.05). The quality of the CBCT surface volume-rendered images acquired at a constant threshold varied across different exposure conditions. Conclusion: These results proved that existing 3D imaging techniques were satisfactorily accurate for clinical applications, and that optimizing the variables that affected image quality, such as the exposure parameters, was critical for image acquisition.

• The korean journal of orthodontics
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• v.51 no.2
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• pp.77-85
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• 2021

Objective: To evaluate the accuracy of a multi-stage convolutional neural network (CNN) model-based automated identification system for posteroanterior (PA) cephalometric landmarks. Methods: The multi-stage CNN model was implemented with a personal computer. A total of 430 PA-cephalograms synthesized from cone-beam computed tomography scans (CBCT-PA) were selected as samples. Twenty-three landmarks used for Tweemac analysis were manually identified on all CBCT-PA images by a single examiner. Intra-examiner reproducibility was confirmed by repeating the identification on 85 randomly selected images, which were subsequently set as test data, with a two-week interval before training. For initial learning stage of the multi-stage CNN model, the data from 345 of 430 CBCT-PA images were used, after which the multi-stage CNN model was tested with previous 85 images. The first manual identification on these 85 images was set as a truth ground. The mean radial error (MRE) and successful detection rate (SDR) were calculated to evaluate the errors in manual identification and artificial intelligence (AI) prediction. Results: The AI showed an average MRE of 2.23 ± 2.02 mm with an SDR of 60.88% for errors of 2 mm or lower. However, in a comparison of the repetitive task, the AI predicted landmarks at the same position, while the MRE for the repeated manual identification was 1.31 ± 0.94 mm. Conclusions: Automated identification for CBCT-synthesized PA cephalometric landmarks did not sufficiently achieve the clinically favorable error range of less than 2 mm. However, AI landmark identification on PA cephalograms showed better consistency than manual identification.

• Imaging Science in Dentistry
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• v.42 no.4
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• pp.243-247
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• 2012

Purpose: This study was performed to compare the inverted digital images and film-based images of dry pig mandibles to measure the periodontal bone defect depth. Materials and Methods: Forty 2-wall bone defects were made in the proximal region of the premolar in the dry pig mandibles. The digital and conventional radiographs were taken using a Schick sensor and Kodak F-speed intraoral film. Image manipulation (inversion) was performed using Adobe Photoshop 7.0 software. Four trained examiners made all of the radiographic measurements in millimeters a total of three times from the cementoenamel junction to the most apical extension of the bone loss with both types of images: inverted digital and film. The measurements were also made in dry mandibles using a periodontal probe and digital caliper. The Student's t-test was used to compare the depth measurements obtained from the two types of images and direct visual measurement in the dry mandibles. A significance level of 0.05 for a 95% confidence interval was used for each comparison. Results: There was a significant difference between depth measurements in the inverted digital images and direct visual measurements (p>|t|=0.0039), with means of 6.29 mm ($IC_{95%}$:6.04-6.54) and 6.79 mm ($IC_{95%}$:6.45-7.11), respectively. There was a non-significant difference between the film-based radiographs and direct visual measurements (p>|t|=0.4950), with means of 6.64mm($IC_{95%}$:6.40-6.89) and 6.79mm($IC_{95%}$:6.45-7.11), respectively. Conclusion: The periodontal bone defect measurements in the inverted digital images were inferior to film-based radiographs, underestimating the amount of bone loss.

• Journal of the Korean Society of Costume
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• v.63 no.2
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• pp.14-28
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• 2013

This study attempts to systematically analyze a red carpet style. I have researched the Academy Awards called representative film awards which symbolizes international fame and the Grammy Awards which is the most prestigious award in the music industry by subdividing into formative elements such as silhouette, color, fabric, pattern, detail, accessory, fashion image, and so on from 2000 to 2012. Firstly, when it comes to silhouette, mermaid silhouette accounts for the highest proportion in the Academy Awards. Compared to this, fit silhouette is shown almost the same percentage as the mermaid silhouette in the Grammy Awards. Secondly, with regard to color, black color has not only the highest percentage but also examples of different unit forms such as various color, showy gradation and single colors. Various colors in the Grammy Awards have similar percentage in comparison with the Academy Awards. Thirdly, in terms of fabric, silky material is often used most, which looks like putting more weight on dresses for the formative elements of clothes. Fourthly, in pattern, patternless dresses are represented by high percentage at both the Academy Awards and Grammy Awards. Dresses with patterns have mild, stylistic elements and geometric designs. The Grammy Awards shows many different unique patterns, color and size, compared to the Academy Awards. Fifthly, in detail, frill and ruffle ornaments are shown most at the Academy Awards and Grammy Awards. Especially in the Grammy Awards, beads ornaments are used most. Sixthly, in accessory, there are many accessories of graceful, elegance styles in the Academy Awards. On the contrary to this, there are many accessories to effect on many performances of large, fancy, unique styles. Seventhly, elegance images of a goddess style among fashion images emerge as fashion of the Academy Awards. In spite of romantic styles in the Grammy Awards, many various images are the same rate as there, which means different appearance of experiment and sensational styles.

• The Korean Journal of Nuclear Medicine
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• v.25 no.2
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• pp.186-191
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• 1991

Radionuclide cardiac studies lend themselves exceptionally well to functional imaging. This is especially true for gated blood pool scan (GBP). Making functional images is also possible in radionuclide angiocardiography (RNAC). In this study we tried to validate the functional images obtained from RNAC by comparing it with GBP. Twenty three patients (16 patients with coronary artery diseases, 5 with hypertensive heart diseases, and 2 with nonspecific chest pains) underwent simultaneous RNAC and GBP at the same position (LAO $45^{\circ}$). From both studies, global ejection fraction, regional ejection fraction, phase image, amplitude image, stroke image, paradox image, maximum ejection and maximum filling rates were obtained. Global ejection fraction are almost same in both studies. Regional ejection fractions of apex and inferior portion of left ventricle calculated from RNAC are well correlated with those of GBP. Phase and paradox image, maximum ejection and maximum filling rates were obtained. Global ejection fraction are almost same in both studies. Regional ejection fractions of apex and inferior portion of left ventricle calculated from RNAC are well correlated with those of GBP. Phase and paradox images of RNAC are very similar to those of GBP. However, amplitude and stroke images are different. Regional ejection fractions of the left ventricular base, maximum ejection and maximum filling rates obtained from RNAC are significantly different from those of GBP. In conclusion, albeit all of functional images of RNAC is not same as GBP, regional walt motions and global left ventricular function are expected to be successfully analyzed by phase and paradox image and ejection fraction.

• Imaging Science in Dentistry
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• v.40 no.2
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• pp.63-68
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• 2010

Purpose : To compare the CT numbers on 3 cone-beam CT (CBCT) images with those on multi-detector CT (MDCT) image using CT phantom and to develop linear regressive equations using CT numbers to material density for all the CT scanner each. Materials and Methods : Mini CT phantom comprised of five 1 inch thick cylindrical models with 1.125 inches diameter of materials with different densities (polyethylene, polystyrene, plastic water, nylon and acrylic) was used. It was scanned in 3 CBCTs (i-CAT, Alphard VEGA, Implagraphy SC) and 1 MDCT (Somatom Emotion). The images were saved as DICOM format and CT numbers were measured using OnDemand 3D. CT numbers obtained from CBCTs and MDCT images were compared and linear regression analysis was performed for the density, $\rho$ ($g/cm^3$), as the dependent variable in terms of the CT numbers obtained from CBCTs and MDCT images. Results : CT numbers on i-CAT and Implagraphy CBCT images were smaller than those on Somatom Emotion MDCT image (p<0.05). Linear relationship on a range of materials used for this study were $\rho$=0.001H+1.07 with $R^2$ value of 0.999 for Somatom Emotion, $\rho$=0.002H+1.09 with $R^2$ value of 0.991 for Alphard VEGA, $\rho$=0.001H+1.43 with $R^2$ value of 0.980 for i-CAT and $\rho$=0.001H+1.30 with $R^2$ value of 0.975 for Implagraphy. Conclusion: CT numbers on i-CAT and Implagraphy CBCT images were not same as those on Somatom Emotion MDCT image. The linear regressive equations to determine the density from the CT numbers with very high correlation coefficient were obtained on three CBCT and MDCT scan.

• Korean Journal of Korean Medical Institute of Dermatology and Aesthetics
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• v.1 no.1
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• pp.98-113
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• 2005

This paper provides comparison and analysis between brand images of Korean herbal cosmetics and general, imported cosmetic brands, focusing on product's symbolic and functional images. The objective is to evaluate brand images of Korean herbal cosmetics to suggest a powerful brand image strategy that will be different and competitive. Data collection was performed on 300 adult women who were over 20 years of age and lived in Seoul or KyongKi area. Analysis was carried out using SPSS version 11.5 and frequency analysis, T-Test and $X^2$ verification was also performed. Analysis results for brand images of Korean herbal cosmetics are as follows. First, satisfaction scale as a purchase feature for users of Korean herbal cosmetics were 'Normal' 51.5%, 'Satisfactory' 35.1%, 'Very Satisfactory' 8.2% and 'Unsatisfactory' 5.2%. Regarding improvements, 'Efficacy, Effect' was the highest with 46%. Second, 'SEOLHWASOO' and 'BAEKOKSENG' among Korean herbal cosmetic brands, 'IOPE' and 'ISA KNOX' among general cosmetic brands and 'LANCOME' and 'CHANEL' among imported cosmetic brands displayed high recognition. Third, the symbolic and functional images of Korean herbal cosmetic brands were seen to be better compared to their general and imported counterparts. Especially, product related features of Korean herbal cosmetic brands received a more positive response compared to imported brands, which suggests that with research and improvement regarding non-product related features, functional images of herbal brands may be appraised ahead of imported brands. Fourth, there is a significant difference in brand preference according to the satisfaction of groups who actually use herbal cosmetics and the purchasing attitudes of groups who do not. Therefore, an active relationship marketing strategy is required to maximize satisfaction and to elicit favorable attitudes. By developing functional native ingredients, constructing data that can prove its efficacy and effects, and appealing its unique, differentiated symbolic value together with Orientalism, herbal medicines will be able to take off to be acknowledged worldwide.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.4
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• pp.630-640
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• 2008

The purpose of this study was to investigate and make comparison of clothing images presented in women's formal and casual brands. The data were collected from 39 formal brands out of 155 and 64 casual brands out of 256 in Korea Fashion Brand Annual in 2005/2006. 316 words selected were classified into five clothing images according to the definition of previous researches and analyzed according to age ranges and price zones of brands. The results were as follows: 1) Formal brands focused on thirties and forties in age ranges and better and prestige in price zones, while casual brands centered on twenties in age range and better and volume in price zones. 2) Luxury, modem and feminine were more frequent words than others both in formal and casual brands, but elegant was found most frequently in formal brands, while comfortable, chic and simple were found frequently in casual brands. 3) Clothing images were classified into four types and appeared in elegance, modernity, individuality, and activeness order in formal brands, while clothing images in casual brands were classified into five types including youthfulness and appeared in elegance, activeness, modernity, individuality, and youthfulness order. 4) Elegance was a highly presented as clothing image in all the age ranges except thirties of formal brands but modernity and activeness with elegance were presented in price zones of casual brands. This study found that there were differences in clothing images in women's formal and casual brands.