• Journal of The Korean Radiological Technologist Association
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• v.25 no.1
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• pp.19-19
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• 1999

We evaluated the effectiveness of continuous spot projection(CSP) for the diagnosis of choledochocele on endoscopic retrograde cholangiography ( ERC ) We performed of 37 patients, who had choledochocele symptom. This study was classified into general ERC

• Journal of radiological science and technology
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• v.41 no.4
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• pp.297-304
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• 2018

This study proposes measures and methods to reduce healthcare associated infections by comparing and analyzing the bacterial contamination level before and after putting on personal protective equipment (PPE) on the test equipment and the contact infected patients getting chest PA projections. Among the 50 inpatients who were diagnosed with C. difficile, MRSA, and VRE, 28 patients who were instructed to undergo chest PA projection and follow-up were chosen, The 3 parts that come in contact with the detector, chin, chest, and hands, were designated for all, and the bacterial contamination level before and after disinfection and before and after putting PPE was determined. Statistical analysis was performed using Medcalc version 14, and quantitative analysis was performed using paired student t-test, with statistical significance being noted at p<0.05. Results for the comparison of the mean values before and after disinfection of the detector, chin (3.000), chest (2.000), and hands (3.430), showed that the number of bacteria after disinfection was lower than it was before disinfection. Analyzing for each part before and after disinfection, there were statistically significant differences for the chin, chest, and hands (p<0.01). Results for the comparison of the mean values before and after putting on PPE, chin (2.202), chest (2.140), and hands (4.213), showed that the number of bacteria after putting on PPE was lower than it was before putting on PPE. Analyzing for each part before and after putting on PPE, there were statistically significant differences for the chin, chest, and hands (p<0.03). As a result, it was confirmed that the number of bacteria after putting on PPE was lower than it was before putting it on. In the future, expanding the research scope for contact infected patients will establish standards for quarantine guidelines depending on the way it spreads, and contribute to the prevention of healthcare associated infections.

• Journal of Korea Multimedia Society
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• v.7 no.1
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• pp.27-34
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• 2004

This thesis proposes a face detection algorithm using the color and edge informations in color image. The proposed algorithm segments skin color by Cb and Cr in YCbCr coordinates. Then face candidate regions are made after morphological filtering and labeling. For the regions, the Sobel vortical operation and horizontal projection are performed in the Y luminance components. The peak value indicates the eye location. Similarly, the chin location is detected by the Sobel horizontal operation and horizontal projection. The computer simulation shows that the proposed method gains similar detection rates of previous method and prevent facial region from including neck by detection of chin.

• The korean journal of orthodontics
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• v.49 no.1
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• pp.3-11
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• 2019

Objective: The purpose of this study was to investigate the influence of heritability on the craniofacial soft tissue cephalometric characteristics of monozygotic (MZ) twins, dizygotic (DZ) twins, and their siblings (SIB). Methods: The samples comprised Korean adult twins and their siblings (mean age, 39.8 years; MZ group, n = 36 pairs; DZ group, n = 13 pairs of the same gender; and SIB group, n = 26 pairs of the same gender). Thirty cephalometric variables were measured to characterize facial profile, facial height, soft-tissue thickness, and projection of nose and lip. Falconer's method was used to calculate heritability (low heritability, $h^2$ < 0.2; high heritability, $h^2$ > 0.9). After principal components analysis (PCA) was performed to extract the models, we calculated the intraclass correlation coefficient (ICC) value and heritability of each component. Results: The MZ group exhibited higher ICC values for all cephalometric variables than DZ and SIB groups. Among cephalometric variables, the highest ${h^2}_{(MZ-DZ)}$ and ${h^2}_{(MZ-SIB)}$ values were observed for the nasolabial angle (NLA, 1.544 and 2.036), chin angle (1.342 and 1.112), soft tissue chin thickness (2.872 and 1.226), and upper lip thickness ratio (1.592 and 1.026). PCA derived eight components with 84.5% of a cumulative explanation. The components that exhibited higher values of ${h^2}_{(MZ-DZ)}$ and ${h^2}_{(MZ-SIB)}$ were PCA2, which includes facial convexity, NLA, and nose projection (1.026 and 0.972), and PCA7, which includes chin angle and soft tissue chin thickness (2.107 and 1.169). Conclusions: The nose and soft tissue chin were more influenced by genetic factors than other soft tissues.

• The korean journal of orthodontics
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• v.47 no.2
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• pp.108-117
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• 2017

Objective: To investigate the effects of frontal facial type (FFT) and sex on preferred chin projection (CP) in three-dimensional (3D) facial images. Methods: Six 3D facial images were acquired using a 3D facial scanner (euryprosopic [Eury-FFT], mesoprosopic [Meso-FFT], and leptoprosopic [Lepto-FFT] for each sex). After normal CP in each 3D facial image was set to $10^{\circ}$ of the facial profile angle (glabella-subnasale-pogonion), CPs were morphed by gradations of $2^{\circ}$ from normal (moderately protrusive [$6^{\circ}$], slightly protrusive [$8^{\circ}$], slightly retrusive [$12^{\circ}$], and moderately retrusive [$14^{\circ}$]). Seventy-five dental students (48 men and 27 women) were asked to rate the CPs ($6^{\circ}$, $8^{\circ}$, $10^{\circ}$, $12^{\circ}$, and $14^{\circ}$) from the most to least preferred in each 3D image. Statistical analyses included the Kolmogorov-Smirnov test, Kruskal-Wallis test, and Bonferroni correction. Results: No significant difference was observed in the distribution of preferred CP in the same FFT between male and female evaluators. In Meso-FFT, the normal CP was the most preferred without any sex difference. However, in Eury-FFT, the slightly protrusive CP was favored in male 3D images, but the normal CP was preferred in female 3D images. In Lepto-FFT, the normal CP was favored in male 3D images, whereas the slightly retrusive CP was favored in female 3D images. The mean preferred CP angle differed significantly according to FFT (Eury-FFT: male, $8.7^{\circ}$, female, $9.9^{\circ}$; Meso-FFT: male, $9.8^{\circ}$, female, $10.7^{\circ}$; Lepto-FFT: male, $10.8^{\circ}$, female, $11.4^{\circ}$; p < 0.001). Conclusions: Our findings might serve as guidelines for setting the preferred CP according to FFT and sex.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2237-2239
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• 1998

A limitation is assumed that In this paper, a generalized method is proposed to extract a period of a motion of on object. To detect a periodic motion, we put restrictions on a stationary camera and on a motion of an object. We ca derive the necessary and sufficient condition that an image sequence consists of the projection of the periodic motion by the affine transformation that is a reasonally good approach to the perspective projection. The difficulty of detecting its periodic motion is to select its have period in sequence and to define its width.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.575-578
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• 2005

Topographical images, in case of aerial or satellite images, are usually similar in colors and textures, and complex in shapes. Thus we have to use shape features of images for efficiently retrieving a query image from topographical image databases. In this paper, we propose a shape feature extraction method which is suitable for topographical images. This method, which improves the existing projection in the Cartesian coordinates, performs the projection operation in the polar coordinates. This method extracts three attributes, namely the number of region pixels, the boundary pixel length of the region from the centroid, the number of alternations between region and background, along each angular direction of the polar coordinates. It extracts the features of complex shape objects which may have holes and disconnected regions. An advantage of our method is that it is invariant to rotation/scale/translation of images. Finally we show the advantages of our method through experiments by comparing it with CSS which is one of the most successful methods in the area of shape feature extraction

• Journal of The Korean Radiological Technologist Association
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• v.25 no.1
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• pp.283-291
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• 1999

• Journal of applied mathematics & informatics
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• v.16 no.1_2
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• pp.621-632
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• 2004

Multiresoluton analysis(MRA) of space of square integrable functions defined on whole entire line has been well-known. But for many applications, MRA on bounded interval was required and studied. In this paper we give a MRA for $L^2$(0, 1) by means of periodic wavelets based on regular MRA for $L^2$(R) and give the convergence of partial sums.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.19 no.1
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• pp.123-136
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• 1989

The purpose of this study was to decide the diagnostic value of transmaxillary and transcranial projection in the evaluation of mandibular condyles. Five dry skulls with intact anatomic structure were selected for this study and the artificial osteophytes were attached to 9 different are as of the mandibular condyle. Ninety transcranial and forty-five transmaxillary radiographs were taken and then the radiographs were evaluated three times. The results were as follows; In transcranial radiographs, superocentral osteophyte was easily observed in closing state than in opening state (p<0.05). But there were no significant differences in other locations (p>0.05). The osteophytes on the medial and central portion easily observed at the transmaxillary projection than transcranial projection (p<0.05), but there was no significant difference on the lateral portion (p>0.05). The osteophytes on the superior (p<0.01) and posterior (p<0.01.) portion were easily observed at the transmaxillary projection than transcranial projection, but there was no significant difference on the anterior portion (p >0.05). The more laterally located osteophytes (p<0.01) at the transcranial projections were easily observed. The more posteriorly located osteophytes (p<0.05) at the transmaxillary projections were easily observed.