• 전력전자학회논문지
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• 제26권4호
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• pp.298-301
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• 2021

A mechanical angle estimator is presented in this study to achieve the sensorless control of permanent magnet synchronous motor (PMSM) used in driving a reciprocating compressor. Braking the PMSM at a specific mechanical angular position is critical for the silent stoppage of the reciprocating compressor. The performance of conventional mechanical angle observers used in reciprocating compressor drives can be seriously affected according to gains of the speed controller because such observers rely on the magnitude of current ripples. A speed ripple-based mechanical angle estimator is proposed to solve this problem. Experimental results showed the effectiveness of the proposed method.

• Imaging Science in Dentistry
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• 제44권3호
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• pp.213-220
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• 2014

Purpose: This study was performed to determine the efficacy of observers' prediction for the need of bone grafting and presence of perioperative complications on the basis of cone-beam computed tomography (CBCT) and panoramic radiographic (PAN) planning as compared to the surgical outcome. Materials and Methods: One hundred and eight partially edentulous patients with a need for implant rehabilitation were referred for preoperative imaging. Imaging consisted of PAN and CBCT images. Four observers carried out implant planning using PAN image datasets, and at least one month later, using CBCT image datasets. Based on their own planning, the observers assessed the need for bone graft augmentation as well as complication prediction. The implant length and diameter, the need for bone graft augmentation, and the occurrence of anatomical complications during planning and implant placement were statistically compared. Results: In the 108 patients, 365 implants were installed. Receiver operating characteristic analyses of both PAN and CBCT preoperative planning showed that CBCT performed better than PAN-based planning with respect to the need for bone graft augmentation and perioperative complications. The sensitivity and the specificity of CBCT for implant complications were 96.5% and 90.5%, respectively, and for bone graft augmentation, they were 95.2% and 96.3%, respectively. Significant differences were found between PAN-based planning and the surgery of posterior implant lengths. Conclusion: Our findings indicated that CBCT-based preoperative implant planning enabled treatment planning with a higher degree of prediction and agreement as compared to the surgical standard. In PAN-based surgery, the prediction of implant length was poor.

• 한국실내디자인학회논문집
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• 제21권1호
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• pp.68-77
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• 2012

Appreciating the aspect of modem architecture requires not only the comprehension of the nature of design and architects' ways of thinking and expression but also observers' views on buildings and their perceptive/cognitive stages. This calls for an in-depth study on the "system of phenomenological perceptions" that works as a new architectural experience system. The system of phenomenological perceptions makes it possible to specify the individual process of understanding architecture, that is, hands-on experiences, participations, feelings, perceptions, and cognition. The value of user experience and cognition has been emphasized by philosophical and aesthetical concepts as well. Therefore, in order to better appreciate the modern architecture, this study suggests theoretical consideration to "orientation and event" that are crucial elements in understanding a phenomenological view and materializing actual space formation. This offers the cognitive system with which we analyze modem architecture and comprehensive expressional methods. In other words, this study contemplates the system of phenomenological perceptions from an existential spatial perspective by structurizing the system of the orientation and the event in order to segmentalize users' current locations, potential directions, the relations with spaces, continual vie'wpoints as well as buildings' functions and interior and exterior division. The system of phenomenological perceptions helps understand and systemize modern architecture through a system based on relations between sensation, perception, cognition, sensitivity, and rationality. This creates a new cognitive system employing the concept of the orientation and the event, which is different from a normal cognitive system basing on the sense of vision. When observers appreciate space, they tend to relate the space to a certain event and to remember their experiences in it. During the process, they draw borders of the space in which the event takes place and give shape to their experiences including actions, movements, cognition and sensation. The process leads to the formation of "placeness," and here, the concept of the orientation comes in as the location and the center of the placeness. This study proves that a determined orientation coupled with individual experience and events settles the place ness; detailed elements in the cognitive system have close relations with one another; the orientation, actions, events, and places are the factors that materialize observers' architectural experience.

• 복식문화연구
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• 제20권5호
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• pp.621-634
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• 2012

With comparative analysis of running-type brassieres on the market about suitability for middle-aged women, this study is to provide basic data of running-type brassieres' pattern which is highly suitable. In the pursuit of this purpose, this study carried out wearing experiment targeting 3 middle-aged women with normal body shape which is 85B of chest circumference. The result is as follows. The significant difference was recognized in the breast. The products were rated in order of C>A>B>D, E, F, G>H by the observers, and C>B>D>A>F>E=G>H by the subjects. The significant difference was recognized in the armhole area. The products were ranked in the order of C, D>B, G, E>A, F, H by the observes and D, C>B>G>F>A>H by the subjects. The significant difference was also recognized in 6 categories(14~19) for the torso. According to the overall average values, the products were rated in the order of B, C, D>A, D, F, G by the observers and B=D>C>H>F>G>A>E by the subjects. The overall evaluation exhibited the significant difference. The products were ranked in the order of D>C>E>B>H>A>G>F by both observers and subjects. Therefore it was confirmed that the product D was appropriate in general. To conclude of comparative analysis about 8 kinds of running-type brassieres on the market, the average values of the product C and D in all categories had high marks for each category. The product C was comfortable and capable of covering the breast well, however, a gap was formed in outside-up part. The product D, made from lacy fabric, was very comfortable and well-fitted but there was inconsistency between the mold-cup and the breast shape.

• 아동학회지
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• 제9권1호
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• pp.93-118
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• 1988

Systematic Training for Effective Parenting, developed by Dinkmeyer and McKay, is a parent education program that emphasizes social-emotional development. The present research studied the applicability of STEP to Korean mothers by examining changes in mothers' self-concept, mother's child-rearing attitudes, and children's behavior. The subjects of this study were 43 mothers of a kindergarten in Chonju City. 25 mothers were assigned to the control group and 18 mothers to the experimental group. Primary observes, consisting of 43 fathers of kindergarten children, and secondary observers, consisting of 43 Woosuk University students observed mothers' child-rearing attitudes and children's behavior. Instruments included the self-concept test by Jung Woonsik, Schaefer's Maternal Behavior Research Instrument, O Kiseon's Parent Child Relationship Test, Fear's parent questionnaire, and McKay's Adlerian Parental Assessment of Child Behavior. The mothers' child-rearing attitudes and the children's behavior are recorded by the observers and were compared with mothers' responses. The data were analyzed by MANOVA (multivariate analysis of variance), and ANOVA (analysis of variance). While the MANOVA showed no significant difference between the control and the experimental groups in changing the mothers' self-concept, differences in 5 of the 8 subfactors showed that STEP implemented positive change in the self-identity, self-satisfaction, self-behavior, personal self and family self in the experimental group. The MANOVA showed a significant difference between the two groups in changing the mothers' child-rearing attitudes. That is after participating in the STEP program, the mothers of the experimental group showed more significant progress than those of the control group. Mothers' observations of positive change in children's behavior agreed with those of the primary and secondary observers.

• 한국지구과학회지
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• 제29권5호
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• pp.408-418
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• 2008

In this study, solar eclipse records were investigated during the Three Kingdoms era of ancient Korea using astronomical calculations and numerical simulations. Under the condition that the solar eclipses were actually observed at the well known capitals of the Three Kingdoms, I investigated the probabilities that the optimal observation areas of the Early Silla, Goguryeo, and Baekje records would appear around Chinese continent. I found higher probabilities than those suggested by Park and La (1994), although the numerical values are still low, especially in the case of the Early Silla records. On the other hand, the probability that the optimal observation area of the Later Silla records will be present around South Korea is only 13.6%, although the area shows a good match with the known capital. I also analyzed the number distribution of the eclipse records for the Three Kingdoms (except for the latter Silla's) according to the observers' locations: at the optimal observation areas and at the known capitals. And then I compared with the number distribution of all eclipses observable from those locations. From the $\chi^2$-test, I found that the Goguryeo and Baekje records had better representation of their population distributions at the latter regions ($\chi^2$=27.93 and 205.5) than at the former ones ($\chi^2$=34.19 and 211.5). Therefore, it is difficult to conclude that the observers' locations during the Three Kingdoms period were either near China, as suggested by Park and La, or in the Korean peninsula, solely based on these results. It is thus recommended that more studies are required to confirm the real observers' locations during the Three Kingdoms era.

• 한국안광학회지
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• 제6권2호
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• pp.129-137
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• 2001

정상 한국인 청년 100명의 안구돌출계를 측정하였다. Hertel 안구돌출계를 사용하여 측정한 검사대상 전체의 평균 안구돌출계는 검사자 A, B 각각의 측정결과에서 우안에서는 $14.8{\pm}0.51mm$와 $13.7{\pm}0.42mm$였고, 좌안에서는 $14.2{\pm}0.46mm$와 $13.6{\pm}0.42mm$로 나타났으며 우안의 안구돌출계치가 좌안보다 약간 더 높았다. 청년 남 여에서 양안의 차이 및 시력의 차이에 따른 안구돌출계치는 유의성 있는 차이가 없었다. A, B 두 검사자가 전체 대상자 100명에 대해 실시한 측정에서 각 대상자에 대한 측정값의 변위계수들의 전체 평균은 각각 우안에서는 3.53%와 3.10%였고, 좌안에서는 3.32%와 3.11%였다. 외안와연간 평균거리는 A, B 각각의 측정결과에서 남성에서는 $106.7{\pm}1.13mm$와 $108.4{\pm}1.08mm$였고, 여성에서는 $103.4{\pm}1.23mm$와 $104.8{\pm}1.02mm$였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제41권
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• pp.31.1-31.7
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• 2019

Background: To test the hypothesis that in profile smiling view, for ideal aesthetics, a tangent to the labial face of the maxillary central incisor crowns should be approximately parallel to the true vertical line and thereby perpendicular to the true horizontal line. Methods: An idealized female image was created with computer software and manipulated using the same software to construct an "ideal" female profile image with proportions, and linear and angular soft tissue measurements, based on currently accepted criteria for idealized Caucasian profiles. The maxillary incisor labial face tangent was altered in 5° increments from 70 to 120°, creating a range of images, shown in random order to 70 observers (56 lay people and 14 clinicians), who ranked the images from the most to the least attractive. The main outcome was the preference ranks of image attractiveness given by the observers. Results: The most attractive inclination of a tangent to the labial face of the maxillary incisor crowns in profile view in relation to the true horizontal line was 85°, i.e. 5° retroclined from a perpendicular 90° inclination. The most attractive range appears to be between 80 and 90°. Excessive proclination appeared to be less desirable than retroclination. Beyond 105° most observers recommend treatment. Conclusion: In natural head position, the ideal inclination of the maxillary incisor crown labial face tangent in profile view will be approximately parallel to the true vertical line and thereby approximately perpendicular to the true horizontal line.

• 대한족부족관절학회지
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• 제16권1호
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• pp.53-57
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• 2012

Purpose: To study computerized measurements of angular parameters on 100% and 150% resized digital radiography of hallux valgus deformity Materials and Methods: 30 digital radiography of standing foot anteroposterior view of hallux valgus patients were included. Two observers(A, B) independently measured hallux valgus angle (HVA), 1-2 intermetatarsal angle (IMA), and distal metatarsal articular angle (DMAA) in two times on both 100%-size and 150% magnified images respectively, using computerized measurement software tools. The results were interpreted with the statistical software program, Statistical Analysis System, version 9.2. Results: In repeated measurements of each observer, measurements on 150% magnified image showed no differences of all three parameters and with 100%-size image, there were differences of HVA (observer A) and 1-2 IMA (observer B) (p>0.05). When testing interobserver reliability, both observers showed differences in measurement of HVA and DMAA (p<0.05), but no differences in measurement of 1-2 IMA in both images. Within the 95% confidence interval, limits of error of measurements between two observers on HVA, IMA and DMAA were $2.7^{\circ}$ $1.4^{\circ}$ and $5.0^{\circ}$ respectively in 100%-size images, and $2.6^{\circ}$, $1.6^{\circ}$ and $4.7^{\circ}$ respectively in 150% magnified images. Conclusion: In computerized measurements for angular parameters of hallux valgus with digital radiography, 150% magnified images showed intraobserver reliability. Both 100% and 150% magnified images failed to show interobserver reliability. Measurement of 1-2 IMA in both 100% and 150% images showed less interobserver error.

• Imaging Science in Dentistry
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• 제48권4호
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• pp.245-254
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• 2018

Purpose: To assess the effects of object position in the field of view (FOV) and application of a metal artifact reduction (MAR) algorithm on the diagnostic accuracy of cone-beam computed tomography (CBCT) for the detection of vertical root fractures(VRFs). Materials and Methods: Sixty human single-canal premolars received root canal treatment. VRFs were induced in 30 endodontically treated teeth. The teeth were then divided into 4 groups, with 2 groups receiving metal posts and the remaining 2 only having an empty post space. The roots from different groups were mounted in a phantom made of cow rib bone, and CBCT scans were obtained for the 4 different groups. Three observers evaluated the images independently. Results: The highest frequency of correct diagnoses of VRFs was obtained with the object positioned centrally in the FOV, using the MAR algorithm. Peripheral positioning of the object without the MAR algorithm yielded the highest sensitivity for the first observer (66.7%). For the second and third observers, a central position improved sensitivity, with or without the MAR algorithm. In the presence of metal posts, central positioning of the object in the FOV significantly increased the diagnostic sensitivity and accuracy compared to peripheral positioning. Conclusion: Diagnostic accuracy was higher with central positioning than with peripheral positioning, irrespective of whether the MAR algorithm was applied. However, the effect of the MAR algorithm was more significant with central positioning than with peripheral positioning of the object in the FOV. The clinical experience and expertise of the observers may serve as a confounder in this respect.