• Korean Journal of Radiology
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• v.21 no.6
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• pp.660-669
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• 2020

Objective: To evaluate the accuracy of a deep learning-based automated segmentation of the left ventricle (LV) myocardium using cardiac CT. Materials and Methods: To develop a fully automated algorithm, 100 subjects with coronary artery disease were randomly selected as a development set (50 training / 20 validation / 30 internal test). An experienced cardiac radiologist generated the manual segmentation of the development set. The trained model was evaluated using 1000 validation set generated by an experienced technician. Visual assessment was performed to compare the manual and automatic segmentations. In a quantitative analysis, sensitivity and specificity were calculated according to the number of pixels where two three-dimensional masks of the manual and deep learning segmentations overlapped. Similarity indices, such as the Dice similarity coefficient (DSC), were used to evaluate the margin of each segmented masks. Results: The sensitivity and specificity of automated segmentation for each segment (1-16 segments) were high (85.5-100.0%). The DSC was 88.3 ± 6.2%. Among randomly selected 100 cases, all manual segmentation and deep learning masks for visual analysis were classified as very accurate to mostly accurate and there were no inaccurate cases (manual vs. deep learning: very accurate, 31 vs. 53; accurate, 64 vs. 39; mostly accurate, 15 vs. 8). The number of very accurate cases for deep learning masks was greater than that for manually segmented masks. Conclusion: We present deep learning-based automatic segmentation of the LV myocardium and the results are comparable to manual segmentation data with high sensitivity, specificity, and high similarity scores.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2327-2331
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• 2015

Purpose: To determine the accuracy of visual inspection with acetic acid (VIA) in detecting high-grade cervical intraepithelial neoplasia (CIN) in pre- and post-menopausal women with atypical squamous cells of undetermined significance (ASC-US) and low grade squamous intraepithelial lesion (LSIL) Papanicolaou (Pap) smears. Materials and Methods: Two hundred women (150 pre-menopausal and 50 post-menopausal) with ASC-US and LSIL cytology who attended the colposcopy clinic, Thammasat University Hospital, between March 2013 and August 2014 were included. All women underwent VIA testing and colposcopy by gynecologic oncologists. Diagnostic values of VIA testing including sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting high-grade CIN were determined using the histopathology obtained from colposcopic-directed biopsy as a gold standard. Results: VIA testing was positive in 54/150 (36%) pre-menopausal women and 5/50 (10%) post-menopausal women. Out of 54 pre-menopausal women with positive VIA testing, 15 (27.8%) had high-grade CIN and 39 (72.2%) had either CIN 1 or insignificant pathology. Ten (10.4%), 43 (44.8%) and 43 (44.8%) out of the remaining 96 pre-menopausal women with negative VIA testing had high-grade CIN, CIN 1 and insignificant pathology, respectively. Out of 5 post-menopausal women with positive VIA testing, there were 4 (80%) women with high-grade CIN, and 1 (20%) women with insignificant pathology. Out of 45 VIA-negative post-menopausal women, 42 (93.3%) women had CIN 1 and insignificant pathology, and 3 (6.7%) had high-grade CIN. Sensitivity, specificity, PPV and NPV of the VIA testing were 59.4%, 76.2%, 32.2% and 90.8%, respectively (60%, 68.8%, 27.8% and 89.6% in pre-menopausal women and 57.1%, 97.7%, 80% and 93.3% in post-menopausal women). Conclusions: VIA testing may be used as a screening tool for detecting high-grade CIN in women with minor cervical cytological abnormalities in a low-resource setting in order to lower the rate of colposcopy referral.

• The Journal of the Korean dental association
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• v.56 no.12
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• pp.686-694
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• 2018

Purpose: The aim of this study was to evaluate the validity of swept-source optical coherence tomography (SS-OCT) for detecting sealant microleakage. Materials and Methods: A total of 31 extracted sound human molar, assigned as suitable for sealant application, were chosen and divided into two groups: (1) no microleakage group and (2) microleakage group by applying sealant using the different methods. All specimens were immersed in 1% methylene blue for 24 h and sectioned to confirm the absence or presence of sealant microleakage as a gold standard method. Subsequently, all the sectioned specimens were digitally photographed using a microscope with a magnification of ${\times}50$. Presence of microleakage was evaluated on a 2-point rating scale. The association of histological method with conventional methods (visual and tactile assessment) and SS-OCT was assessed using a chi-squared test. The intra- and inter-examiner reliability was calculated using Cohen's Kappa. Results: The SS-OCT showed a sensitivity of 0.73 and a specificity of 1.00, while visual and tactile assessment showed a sensitivity of 0.67 and a specificity of 0.86. The inter-examiner reliability of SS-OCT was 0.79, whereas that of the visual and tactile assessment was 0.53. Conclusions: SS-OCT can be used to non-invasively detect sealant microleakage and to monitor pit and fissure sealant in the clinics.

• Journal of the Korea Convergence Society
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• v.9 no.12
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• pp.273-279
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• 2018

This study researched how the refraction error and illumination influence to contrast sensitivity when we wear the circle contact lenses. The study population comprised 16 students and adults(5 of Male, 11 of Female). The study population comprised 16 students and adults(5 of Male, 11 of Female), We measured the contrast sensitivity on uncorrected vision, according to color of circle contact and change the illumination of laboratory. The contrast sensitivity by illumination decreased than unaided vision when they wore the color contact lenses and more increased mesopic than photopic. Compared between black and brown lenses, brown was higher the contrast sensitivity than black. Also emmetropia had significantly differences when we compared the contrast sensitivity of subjects who had emmetropia, myopia and myopia astigmatism whether refractive error has or not. Therefore, it is important to provide sufficient understanding and recognition of color contact lenses.

• The Journal of Korean Academy of Sensory Integration
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• v.12 no.1
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• pp.1-11
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• 2014

Objective : The purpose of this research is understanding relevancy of school ages'ability of sensory process and preference of what they want to play, and studying of main reason of impact of sensory process to preference of what school ages want to play. Methods : During 22 to 24 October 2012, our group evaluated and analyzed ability of sensory process and preference of what children want to play by using Short Sensory Profile (SSP) and Pediatric Interest Profile (PIP) to elementary school children in fourth grade at Kimhae city in Kyungnam province. Results : For the total population of an ability of sensory process and frequency, preference, and proficiency of eight different games, preference of outdoor activities appears to be related to total score of sensitivity to taste and smell and filter of hearing. For preference and proficiency of creative activities appears to be related to sensitivity of taste and smell. Preference of lessons and classes related to total scores of sensitivity of tactile sensation, taste and smell, movement, and filter of hearing, and sensitivity of visual and hearing. Frequency and proficiency of lessons and classes are inter-related to sensitivity of visual and hearing. Conclusion : This research shows that there is no inter-relationship between function of sensory process and preference of what children want to play, however certain games relevantly show the inter-relationship. The research provides the basic data of what the preference of what children want to play and determine what children can play during occupational therapy with plays after studying inter-relationship of school ages'ability of sensory process and games.

• Journal of Sasang Constitutional Medicine
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• v.22 no.1
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• pp.41-48
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• 2010

1. Objective There has been a few trials to diagnose Sasang Constitution by using EEG, but has not been studied intensively. For the purpose of practical diagnosis, the characteristics of EEG for each constitution should be studied first. Recently it has been shown that Sasang Constitution might be related to harm avoidance and novelty seeking in temperament and character profiles. Based on this finding, we propose a visual stimulation method to evoke a EEG response which may discriminate difference between constitutional groups. Through the experiment with this method, we tried to reveal the characteristics of EEG of each constitutional groups by the method of event-related potentials. 2. Methods: We used facial visual stimulation to verify the characteristics of EEG for each constitutional groups. To reveal characteristic in sensitivity and latency of response, we added several levels of noise to facial images. 6 male subjects(2 Taeeumin, 2 Soyangin, 2 Soeumin) participated in this study. All subjects are healthy 20's. To remove artifacts and slow modulation, we removed EOG contaminated data and renormalization is applied. To extract stimulation related components, normalized event-related potential method was used. 3. Results: From Oz channels, it is verified that facial image processing components are extracted. For lower level noise, components related to the visual stimulation were clearly shown in Oz, Pz, and Cz channels. Pz and Cz channels show differences among 3 constitutional groups in maximum around 200 msec. Especially moderate level of noise looks appropriate for diagnosis. 4. Conclusion: We verified that the visual stimulation with facial emotion might be a good candidate to evoke the differences between constitutional groups in EEG response. The differences shown in the experiment may imply that the process of emotion has distinct tendencies in latencies and sensitivity for each consitutional group. And this distinction might be related to the temperament profile of consitutional groups.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.11a
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• pp.245-247
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• 2014

본 논문은 human visual system(HVS)에 따른 주파수 민감도와 공간에서 다양한 특성들을 구현하기 위한 신호처리 방법을 개발하였다. 인간의 눈은 주파수 성분에 따라 민감도가 다르며 초점에서 멀수록 인지 가능한 해상도가 떨어진다. 주파수 민감도를 구현하기 위해서 본 논문은 영상 신호의 에너지 스펙트럼 모양이 contrast sensitivity function(CSF)의 모양이 되도록하여 영상 신호의 에너지를 증가시켰으며 신호 방향에 적응적인 multiband energy scaling 방법을 개발하였다. 기존의 시스템에서 능률만을 향상시키는 기존의 분석 모델과 비교하면 개발한 방법은 HVS에 좀 더 적절하고 선호되게 영상 신호를 처리할 수 있다.

• Korean Institute of Interior Design Journal
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• no.39
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• pp.28-36
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• 2003

The yardstick of value has transformed into personal and sensitive one after it went through an Industrial society. The space in the society of sensitivity is defined by a semiotic character rather than as a physical object aimed at satisfying basic desire. Through this character, space makes a meaning and comes to exist an exchanging productive place. Environmental transformation is demanding further ample sensitive expression. In connection with the above, this thesis aims to identify the characteristics of sensitive and human-centered approach and systematize the analogy analysis which is applied to the interior space, classified by elements by introducing the concept of analogic inference in the field of rhetoric and through a diverse genres. As an approach, this thesis is entitled the analogic inference of the field of rhetoric to various art genres, and as a analogic interpretation genre, this thesis Is subdivided it into the fields of literature, image, fashion, flower art, and visual design, and study the analysis of analogic inference as a means of materializing storied space through the connection literature with design.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.454-458
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• 2004

A new algorithm for the rate control of videos considering the sensitivity of the human visual system is presented. The method adopts the three-step structure of MPEG2 TM5 rate control, and a new measure of macroblock activity based on spatio-temporal sensitivity is introduced for the adaptive quantization. Experimental results show that the spatio-temporal activity measure outperforms the spatial activity of TM5 in picture quality.

• Journal of Photoscience
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• v.9 no.2
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• pp.44-46
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• 2002

In the vertebrate retina, rods mediate twilight vision and cones daylight vision. Rods have been purified easily from the retina, and thus the phototransduction mechanism in rods is now well documented. However, it has not been possible to purify cones in large quantities, and therefore, the knowledge on the mechanism in cones is limited. Here we report purification of carp (Cyprinus carpio) cones with a stepwise Percoll gradient. Using purified cells, we compared the phototransduction mechanism between rods and cones. The results showed that both transducin activation and phosphodiesterase activation are less effective, and visual pigment phosphorylation is faster in cones. These differences explain lower light-sensitivity and briefer photoresponse time course in cones.