• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.1
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• pp.22-29
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• 2015

The purpose of this study was to evaluate the eruption patterns of mandibular premolars associated with dentigerous cysts after marsupialization regarding the depth, angulation and root development of impacted teeth. Spontaneous eruption was found in 93% of mandibular premolars after marsupialization. Eruption speed and rate of angulation change were greater in mandibular premolars associated with a cyst than those on the non-cyst side. The group with less matured roots tended to have greater eruption speed and angulation change. The eruption speed and angulation change declined rapidly during the first 6 months after marsupialization. Based on the results of this study, it might be possible to predict the eruption pattern of mandibular premolars associated with a cyst after marsupialization, which would be useful for treatment planning.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.74.2-74.2
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• 2014

We have presented a classic two-ribbon filament eruption occurred in the east side of NOAA active region 11850 at 21:00 UT on 29 September 2013. Interestingly, this filament eruption was not accompanied by any flares and just there was a slight brightening in X-rays, C1.2, associated with the eruption. An accompanying huge CME was appeared at 22:12 UT in the LASCO C2 field of view and it propagates into the interplanetary space with a speed of about 440 km/s. And the related solar proton event (S2) started at 05:05 UT and peaked at 20:05 UT on 30 September 2013. The CME arrival was recorded by the ACE spacecraft around 01:30 UT on 2 October 2013. Around the CME arrival time, the solar-wind speed reached at about 640 km/s and IMF Bz showed southward component (-27 nT). Finally, the filament eruption and the CME cause geomagnetic storm (G2) at 03:00 UT on 2 October 2013. We described the detailed evolution of the filament eruption and its related phenomena such as CME, proton event, geomegnetic storm and so on. In addition, we will discuss about the activation mechanism of the filament eruption without flares.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.90.2-90.2
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• 2013

Filament eruptions are one of the energetic phenomena on the solar surface with flares and coronal mass ejections (CMEs). We observed the whole process of filament eruption that occurred in AR 11305 in association with a C5.6 flare on 2011 September 29th using the Fast Imaging Solar Spectrograph (FISS) and the Solar Dynamics Observatory (SDO). The eruption consists of a slow phase with a transverse speed of ~10 km $s^{-1}$ in 16 minutes and a fast phase with a transverse speed of ~200 km $s^{-1}$ in 3 minutes. Near the beginning of slow phase eruption, preflare brightening occurred beneath the filament in $H{\alpha}$ and some EUV images. The preflare brightening region is associated with a blue-shifted $H{\alpha}$ feature with a speed of ~60 km $s^{-1}$. It appears that this is the outflow from magnetic reconnection which may have occurred at relatively low atmosphere. Our result support the notion that the preflare brightening is a process of magnetic reconnection playing an important role in triggering the filament eruption by deformative the magnetic field lines under the eruptive filament.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.373-384
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• 2003

The purpose of this study was to evaluate the eruption pattern of a cyst-associated mandibular premolar after marsupialization of a dentigerous cyst in children. The result from the twenty two pairs of normalized panoramic radiographs of twenty two patients who underwent neither extraction nor orthodontic traction of the cyst-associated mandibular after marsupialization were as follows. 1. The eruption speed of a cyst-associated premolar was 3.5 times faster than that of the normal contra-lateral premolar(p<0.05). The angulation change of test group was an average of $2.7^{\circ}$ per month. 2. In the change of the level of root formation, the group which had a little root maturity tended to be faster in the eruption speed(p>0.05) and the R1/4 group had a great change in the angulation change(p>0.05). 3. In the change to be with the cusp position index, the eruption speeds were increased to the 30% deviation groups. But, the eruption speed was decreased above that(p>0.05). 4. Group with cyst diminishment rate of more than $80mm^2$ per month showed the fastest eruption speed of all(p<0.05). 5. The mesial angulated teeth in the test group were decreased more rapidly than the distal angulated teeth in the eruption speed(p>0.05). But, increased in the angulation change(p<0.05). 6. There was a tendency of faster tooth eruption with less deviation of tooth axis. Group with tooth axis deviation of less than $15^{\circ}$ showed the fastest angulation change of all(p<0.05). 7. The eruption speed and the angulation change rapidly decreased during the first 6 months following marsupialization. Based on the results of this study, a cyst-associated mandibular premolar erupted more rapidly after marsupializaton. We thought so that it's prognosis was good if the tooth had a little root maturity, a little devitation and cyst lesion healed faster. We recommend that if there is enough space for eruption, orthodontic traction and surgical treatment of the cyst-associated tooth should be postponed 6 months after marsupialization.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.493-499
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• 2022

This paper reports the results of the eruption of a volcano on Jeju Island at a certain rate, and the tumulus formed after the eruption and the basalt that erupted from the middle of Mt. Halla washed up to the sea. We analyzed the speed when basalt underground magma breaks through the neutral zone on the ground with an absolute temperature of about 1000K and explodes at an absolute temperature of 1200K at an altitude of 1950m. The density of combustion gas becomes smaller than the surrounding air due to the plume volcanic eruption, which is the heat flow of the flame column due to buoyancy, and buoyancy is generated and an updraft is formed. Flame pillars are classified as continuous, intermittent, and buoyant flame zones. As the speed of the flame pillar of Mt. Halla (1950m) falls from the highest point it has risen, potential energy is converted into kinetic energy and is caused by the flow of fluid, solving these two equations equal, the volcanic eruption velocity is 87.5 m/s. At this time, the density of magma is inversely proportional to the temperature. Geomunoreum (456m) had an explosion speed of 42.6m/s.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.4
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• pp.357-372
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• 2016

Augustine volcano, located along the Aleutian Arc, is one of the most active volcanoes in Alaska and nearby islands, with seven eruptions occurring between 1812 and 2006. This study monitored the surface displacement before and after the most recent 2006 eruption. For analysis, we conducted a time-series analysis on data observed at the permanent GPS(Global Positioning System) observation stations in Augustine Island between 2005 and 2011. According to the surface displacement analysis results based on GPS data, the movement of the surface inflation at the average speed of 2.3 cm/year three months prior to the eruption has been clearly observed, with the post-eruption surface deflation at the speed of 1.6 cm/year. To compare surface displacements measurement by GPS observation, ENVISAT(Environmental satellite) radar satellite data were collected between 2003 and 2010 and processed the SBAS(Small Baseline Subset) method, one of the time-series analysis techniques using multiple InSAR(Interferometric Synthetic Aperture Radar) data sets. This result represents 0.97 correlation value between GPS and InSAR time-series surface displacements. This research has been completed precise surface deformation using GPS and time-series InSAR methods for a detection of precursor symptom on Augustine volcano.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.50.1-50.1
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• 2010

The New Solar Telescope (NST) at Big Bear Solar Observatory (BBSO) is the recently constructed world largest 1.6 m optical solar telescope on the ground. We took an observation of the north polar limb in H-alpha line center wavelength on 2009 August 26 with the instrument at Nasmyth focus of the NST and found a remarkable small-scale H-alpha eruption from 18:20 UT and 18:45 UT. The eruption occurred with a relatively slow speed of about 10 km/s in early stage and a slight acceleration up to 20-30 km/s in later stage. We also found that the eruption shows a deflection along the pre-existing magnetic field as well as several interesting features such as bifurcation, rotation, horizontal oscillation, and direction and thickness change of its structure during the eruption. In this talk, we will report the observational properties of the small-scale eruption observed by the NST and discuss their implication on magnetic reconnection.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.6
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• pp.528-532
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• 2010

Introduction: There are few reports on tooth eruption through Bio-Oss grafts. To our knowledge, there are no reports on whether teeth can erupt normally through the grafts. The aim of this study was to examine the effect of Bio-Oss grafts on tooth eruption in a canine model. Materials and Methods: In five 10-week-old dogs, the deciduous third mandibular molars in one jaw quadrant of each animal were extracted and the fresh extraction sockets were then filled with Bio-Oss particles (experimental side). No such treatments were performed on the contralateral side (control side). A clinical and radiological evaluation was carried out every other week to evaluate the eruption level of the permanent third mandibular premolars and compare the eruption levels between the two sides. Results: At week 4 after the experiment, the permanent third premolars began to erupt on both sides. At week 12, the crown of the permanent third premolar emerged from the gingiva on both sides. At week 20, the permanent third premolars on both sides erupted enough to occlude the opposing teeth. No significant differences were found between the control and experimental sides in terms of the eruption speed of the permanent third molars. Conclusion: These findings demonstrate that the grafting of Bio-Oss particles into the alveolar bone defects does not affect tooth eruption.

• Journal of The Korean Astronomical Society
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• v.37 no.1
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• pp.41-53
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• 2004

It has been a big mystery what drives filament eruptions and flares. We have studied in detail an X1.8 flare and its associated filament eruption that occurred in NOAA Active Region 9236 on November 24,2000. For this work we have analyzed high temporal (about 1 minute) and spatial (about 1 arcsec) resolution images taken by Michelson Doppler Imager (MDI) onboard the Solar and Heliospheric Observatory, Hoc centerline and blue wing ($-0.6{\AA}$) images from Big Bear Solar Observatory, and 1600 ${\AA}$ UV images by the Transition Region and Corona Explorer (TRACE). We have found that there were several transient brightenings seen in H$\alpha$ and, more noticeably in TRACE 1600 ${\AA}$ images around the preflare phase. A closer look at the UV brightenings in 1600 ${\AA}$ images reveals that they took place near one end of the erupting filament, and are a kind of jets supplying mass into the transient loops seen in 1600 ${\AA}$. These brightenings were also associated with canceling magnetic features (CMFs) as seen in the MDI magnetograms. The flux variations of these CMFs suggest that the flux cancellation may have been driven by the emergence of the new flux. For this event, we have estimated the ejection speeds of the filament ranging from 10 to 160 km $s^{-1}$ for the first twenty minutes. It is noted that the initiation of the filament eruption (as defined by the rise speed less than 20 km $s^{-1}$) coincided with the preflare activity characterized by UV brightenings and CMFs. The speed of the associated LASCO CME can be well extrapolated from the observed filament speed and its direction is consistent with those of the disturbed UV loops associated with the preflare activity. Supposing the H$\alpha$/UV transient brightenings and the canceling magnetic features are due to magnetic reconnect ion in the low atmosphere, our results may be strong observational evidence supporting that the initiation of the filament eruption and the preflare phase of the associated flare may be physically related to low-atmosphere magnetic reconnection.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.89.1-89.1
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• 2012

We have investigated a coronal jet observed near the limb on 2010 June 27 by the Hinode/X-Ray Telescope (XRT), EUV Imaging Spectrograph (EIS), and Solar Optical Telescope (SOT), and the SDO/Atmospheric Imaging Assembly (AIA), Helioseismic and Magnetic Imager (HMI), and on the disk by STEREO-A/EUVI. From EUV (AIA and EIS) and soft X-ray (XRT) images we have identified both cool and hot jets. There was a small loop eruption in Ca II images of the SOT before the jet eruption. Using high temporal and multi wavelength AIA images, we found that the hot jet preceded its associated cool jet by about 2 minutes. The cool jet showed helical-like structures during the rising period. According to the spectroscopic analysis, the jet's emission changed from blue to red shift with time, implying helical motions in the jet. The STEREO observation, which enabled us to observe the jet projected against the disk, showed that there was a dim loop associated with the jet. We have measured a propagation speed of ~800 km/s for the dimming front. This is comparable to the Alfven speed in the loop computed from a magnetic field extrapolation of the HMI photospheric field measured 5 days earlier and the loop densities obtained from EIS Fe XIV line ratios. We interpret the dimming as indicating the presence of Alfvenic waves initiated by reconnection in the upper chromosphere.