• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.48.1-48.1
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• 2010

A numerical simulation study of the solar coronal plasma reveals that a ballooning instability can develop in the course of flux rope merging. When magnetic field lines from different flux ropes reconnect, a new field line connecting farther footpoints is generated. Since the field line length abruptly increases, the field line expands outward. If the plasma beta is low, this expansion takes place more or less evenly over the whole field line. If, on the other hand, the plasma beta is high enough somewhere in this field line, the outward expansion is not even, but is localized as in a bulging balloon. This ballooning section of the magnetic field penetrates out of the overlying field, and eventually the originally underlying field and the overlying field come to interchange their apex positions. This process may explain how a field structure that has stably been confined by an overlying field can occasionally show a localized eruptive behavior.

• Proceedings of the KACD Conference
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• 2001.11a
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• pp.553-553
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• 2001

The purpose of this study is to identificate root canal system including ideal access placement, root curvature, canal configuration, incidence of isthmus in mandibular incisors for success of endodontic treatment. 200 mandibular incisors were selected. The ideal access placement was determimed as follows. The teeth were radiographed from mesiodistal and buccolingual views using intraoral dental film. The image was divided into coronal, middle and apical third using the proximal film. Straight line access was determined by measuring the faciolingual canal width and placing points at midway point between the buccal and lingual wall at the junction of the middle and apical third and at the juntion of coronal and middle third of the root canal.(omitted)

• Proceedings of the KACD Conference
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• 2001.11a
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• pp.560.1-560
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• 2001

To evaluate the micro-shear bond strength of current adhesive systems to cervical and mid-coronal enamel. Materials and Two commercially available resin adhesives were investigated; a self-etching primer system(Clearfil SE Bond, Kyraray) and a one-bottle adhesive system(Single Bond, 3M) intended for use with the total-etch wet-bonding technique were employed. Two regions of enamel, cervical and mid-coronal regions, were chosen from the buccal surface of extracted molars and were then bonded with each adhesive system and submitted to the micro-shear bond test.(중략)

• Proceedings of the KACD Conference
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• 2001.11a
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• pp.562.2-562
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• 2001

The purpose of this study is to identificate root canal system including ideal access placement, root curvature, canal configuration, incidence of isthmus in mandibular incisors for success of endodontic treatment. 200 mandibular incisors were selected. The ideal access placement was determined as follows. The teeth were radiographed from mesiodistal and buccolingual views using intraoral dental film. The image was divided into coronal, middle and apical third using the proximal film. Straight line access was determined by measuring the faciolingual canal width and placing points at midway point between the buccal and lingual wall at the junction of the middle and apical third and at the juntion of coronal and middle third of the root canal.(omitted)

• 한국가시화정보학회:학술대회논문집
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• 2004.12a
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• pp.135-140
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• 2004

Several studies have utilized physical models of the healthy nasal cavity to investigate the relationship between nasal anatomy and airflow. With our experiences of experimental investigations on nasal airflows in normal and abnormal nasal cavity models, we are going to deal with the topic that may contribute to the diagnosis and treatment of nasal diseases. In this paper, airflows in the normal and artificially deformed models, which simulate surgical treatment, are investigated experimentally by PIV. High-resolution CT data and careful surface rendering of computational model with the help of the ENT doctor provide more sophisticated nasal cavity models. The CBC PIV (Correlation Based Correction PIV) algorithm with window offset is used for PIV flow analysis. Average and RMS distributions in sagittal and coronal sections are obtained for inspiratory and expiratory nasal airflows. Comparisons in nasal airflows for both normal and deformed cases are also appreciated. In case of simulations of surgical operations, velocity and RMS distributions in coronal section changes locally, this may cause some difficulties in physiologic functions of noses and may hurt mucosal surface.

• English Language & Literature Teaching
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• v.15 no.2
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• pp.51-70
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• 2009

This study focuses on the asymmetrical realization of homorganic nasal-obstruent stop clusters in English when they occur word medially and word finally. This uneven realization of NC clusters is not only controlled by the place of articulation of the cluster constituents but also by the agreement of voicing feature specifications of the cluster elements. We propose context-sensitive constraints, which are more specified versions than *NC (Pater, 1996, 1999, 2004). The result of the study reveals that homorganic NC clusters consisting of coronal place feature are faithfully realized word finally while they are constrained word medially. The deletion of voiceless post-nasal coronal stop should be considered a new language specific strategy to avoid *NC.

• Journal of the korean academy of Pediatric Dentistry
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• v.6 no.1
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• pp.15-20
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• 1979

Sixty non-vital primary molars of forty six children who were patients at the Pedodontic Department of Seoul University Hospital, aged from 2 years 7 months to 9 years 1 month were performed for coronal pulp therapy. For the evaluation of non-vital pulp therapy, the author observed those teeth both clinically and roentgenographically. The results were as follows: 1. Coronal therapy of non-vital tooth can be accepted as one of the ordinary methods at the view of the save of tooth, time and simplicity. 2. The results were satisfactory 78.3% clinically and 68.3% roentgenographically. 3. The dissatisfactory signs were a) Clinical view There were dissatisfactory signs on 13 cases. (1) 2 teeth had fistulous opening. (2) 11 teeth reacted to purcussion and mobility. b) Roentgenographical view There were dissatisfactory signs on 19 cases. (1) 13 teeth showed roentgenolucency at bifurcation area. (2) 2 teeth showed pathological root resorption. (3) 4 teeth showed periodontal thickening.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.39.1-39.1
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• 2011

Coronal mass ejection (CME) plasmas have been observed in EUV and X-ray passbands as well as in white light. Mass of CME has been determined using polarized brightness observed by the Large Angle and Spectrometric Coronagraph Experiment (LASCO) on board Solar and Heliospheric Observatory (SOHO). Therefore, this mass obtained from the LASCO observation indicates the total CME mass. However, the mass of CME plasma in different temperatures can be determined in EUV and X-ray passbands using observations by SOHO/EIT, STEREO/EUVI, and Hinode/XRT. Prominence/CME plasmas have been observed as absorption or emission features in EUV and X-ray passbands. The absorption features provide a lower limit to cold mass. In addition, the emission features provide an upper limit to the mass of plasmas in temperature ranges of EUV and X-ray. We determine the mass constraints using the emission measure obtained by assuming the prominence/CME structures. This work will address the mass constraints of hot and cold plasmas in CMEs, comparing to total CME mass.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.586-586
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• 2003

In the infected immature tooth with periapical involvement, the pulp is considered to hardly exist in the canal and periapical area. Such a tooth receives apexification procedure, because revascularization of the pulp chamber is in principle not expected. Apexification is beneficial to induce further development of an apex to close the foramina, but does not promote the thickness of the entire canal wall dentin. It may be possible for the pulp to be only partially necrotic and infected when an extremely large communication from the pulp space to the periapical tissues exists with a very young tooth. If this were the case, vital pulp in the apical part of the canal could proliferate new pulp into the coronal pulp space by the successful removal and disinfection of the necrotic infected coronal pulp.(omitted)

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.41.1-41.1
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• 2019

The stability analysis of coronal magnetic structures is important for studying the initiation of solar flares and eruptions. In order to understand the flare onset process, we first reconstructed the 3D coronal magnetic structures of active region 12371 with an M6.5 flare using a nonlinear force-free field (NLFFF) model based on vector magnetic fields. The NLFFFs successfully produce the observed sigmoidal structure which is composed of two branches of sheared arcade loops. The stability analysis were examined for three representative MHD instabilities: the kink, the torus, and the double arc instabilities. Our stability analysis shows that the two branches of sheared arcade loops are quite stable against the kink and torus instabilities, but unstable against the double arc instability before the flare occurrence. Finally, we discuss a probable onset process of the M6.5 flare.