• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.84.3-85
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• 2015

We report a small-scale EUV bright loop associated with the evolution of the fine-scale magnetic discontinuity in the photosphere. Our analysis was carried out by using the high spatial resolution data taken with InfraRed Imaging Magnetograph (IRIM) and the Fast Imaging Solar Spectrograph (FISS). As a result, an extremely narrow dark lane of the intense horizontal magnetic field (width ~ 300 km) is detected parallel to the boundary of the magnetic pore, which is one of the footpoints of the small-scale bright coronal loop. We find that the variation of the net linear polarization inside the dark lane is closely related to the intensity variations of the coronal loop. Based on our results, we suggest that small-scale atmospheric heating such as bright coronal loop seen above the complex pore group may be strongly affected by the evolution of the fine-scale magnetic discontinuity in the photosphere. This is a nice example of solar atmospheric heatings associated with the fine-scale magnetic discontinuity in the photosphere.

• Journal of Positioning, Navigation, and Timing
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• v.5 no.4
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• pp.221-233
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• 2016

This paper deals with performance assessment of the kinematic network-based GPS positioning technique with a view to using it for ellipsoidally referenced bathymetric surveys. To this end, two field trials were carried out on a land vehicle and a surveying vessel. Single-frequency GPS data acquired from these tests were processed by an in-house software which equips the network modeling algorithm with instantaneous ambiguity resolution procedure. The results reveals that ambiguity success rate based on the network model is mostly higher than 99.0%, which is superior to that of the single-baseline model. In addition, achievable accuracy of the technique was accessed at ${\pm}1.6cm$ and 2.7 cm with 95% confidence level in horizontal and vertical component respectively. From bathymetric survey at the West Nakdong River in Busan, Korea, 3-D coordinates of 2,011 points on its bed were computed by using GPS-derived coordinates, attitude, measured depth and geoid undulation. Note that their vertical coordinates are aligned to the geoid, the so-called orthometric height which is widely adopted in river engineering. Bathymetry was constructed by interpolating the coordinate set, and some discussion on its benefit was given at the end.

• The korean journal of orthodontics
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• v.24 no.3 s.46
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• pp.649-658
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• 1994

The purpose of this study was to evaluate the association between incisor root resolution and sex, age, extraction, the magnitude and direction of tooth movement. The sample consisted of 189 randomly selected orthodontic patients, receiving standard edgewise orthodontic treatment in three private orthodontic onces at San Francisco. Pre-treatment and post-treatment periapicals and cephalometric radiographs were digitized. Measurements and superimpositions were made utilizing a computerized cephalometric analysis program. The variables were statistically analyzed. The results were as follows: 1. Mean apical root resorption values were $0.77{\pm}2.08mm$ for upper right central incisor, $0.88{\pm}2.11mm$ for upper left central incisor, $-0.05{\pm}2.09mm$ for lower right central incisor and $0.11{\pm}1.85mm$ for lower left central incisor. Apical root resorption of upper incisor was greater than lowers. 2. No correlation was found between sex and apical root resorption. 3. Apical root resorptions in adolescents were smaller than those in adults. 4. Apical root resorption was not affected by extraction. 5. Apical root resorption values of upper incisor were correlated to the horizontal and vertical movement of apex; Apical root resorption values of lower incisor were correlated to the vertical movement of apex.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.38.1-38.1
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• 2013

We present the Yonsei evolutionary population synthesis (YEPS) models based on the high-resolution empirical spectral energy distributions (SEDs). We have adopted the MILES library in the optical wavelength, and our new models based on the MILES library show good agreements with our previous models presented in the YEPS I. The effect of hot horizontal-branch (HB) stars on the integrated properties of simple stellar populations (SSPs) is again confirmed by our models based on empirical SEDs. In addition, we have extended our empirical models to the near-IR wavelength and predicted the strengths of the calcium II triplet (CaT) and the Paschen triplet (PaT) based on the INDO-US and the Cenarro library. We find that the effect of HB stars and the age of SSPs on the CaT is almost negligible. On the other hands, the PaT models are very sensitive to the existence of hot stars, e.g., HB stars and young turn-off stars, and show very similar results with Balmer lines. Interestingly, the CaT distribution of GCs in NGC 1407, which is at odds with the optical (B-I) color distribution, can be explained by the unique feature of the CaT-[Fe/H] relations that show almost the same equivalent widths in the metal-rich regime. We will also discuss the impact of the second-generation populations on the strength of the CaT.

• Atmosphere
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• v.25 no.2
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• pp.367-374
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• 2015

Korean Peninsula has high potential for occurrence of aviation turbulence. A Korean aviation Turbulence Guidance (KTG) system focused on the Korean Peninsula, named Korean-Peninsula KTG (KP-KTG) system, is developed using the high resolution (horizontal grid spacing of 1.5 km) Local Data Assimilation and Prediction System (LDAPS) of the Korea Meteorological Administration (KMA). The KP-KTG system is constructed first by selection of 15 best diagnostics of aviation turbulence using the method of probability of detection (POD) with pilot reports (PIREPs) and the LDAPS analysis data. The 15 best diagnostics are combined into an ensemble KTG predictor, named KP-KTG, with their weighting scores computed by the values of area under curve (AUC) of each diagnostics. The performance of the KP-KTG, represented by AUC, is larger than 0.84 in the recent two years (June 2012~May 2014), which is very good considering relatively small number of PIREPs. The KP-KTG can provide localized turbulence forecasting in Korean Peninsula, and its skill score is as good as that of the operational-KTG conducting in East Asia.

• Atmosphere
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• v.17 no.1
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• pp.1-15
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• 2007

A constraint based on climatology is introduced to the cost function of the three-dimensional variational assimilation (3dVar) to correct the error of the zonal mean wind structure in the global data assimilation system at Korea Meteorological Administration (KMA). The revised cost function compels the analysis fit to the chosen climatology while keeping the balance between the variables in the course of analysis. The constraint varies selectively with the vertical level and the horizontal scale of the motion. The zonally averaged wind field from European Centre for Medium-Range Weather Forecasts Re-Analysis 40 (ERA-40) is used as a climatology field in the constraint. The constraint controls only the zonally averaged stratospheric long waves with total wave number less than 20 to fix the error of the large scale wind field in the stratosphere. The constrained 3dVar successfully suppresses the erroneous westerly in the stratospheric analysis promptly, and has been applied on the operational global 3dVar system at KMA.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.2
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• pp.119-130
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• 2012

Heat island phenomena in Chuncheon (Korea) were investigated using air temperature measured by automatic weather stations and temperature dataloggers located at rural and urban sites. Numerical simulation of the phenomena was performed using Weather Research and Forecasting Urban Canopy Model (WRF-UCM) and results were compared with the observation. The model was initialized with NCEP/FNL data. The horizontal resolution of the fine domain is 0.33 km. The results of observational analyses show that the intensity of heat island was significantly higher during the nighttime than during the daytime. The highest measured temperature difference between rural and urban site is $3.49^{\circ}C$ and average temperature difference varies between 1.4 and $1.9^{\circ}C$. Good agreement was found between the simulated and observed temperatures. However, significantly overestimated wind speed was found at the urban sites. The linear regression analysis between observed and simulated temperature shows high correlation coefficient 0.96 for urban and 0.94 for rural sites while for wind speed, a very low correlation coefficient was found, 0.30 and 0.55 respectively.

• Journal of dental hygiene science
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• v.20 no.2
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• pp.118-124
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• 2020

The purpose of this comparison of case reports is to introduce the results of the application of new devices for the management of growing Class III malocclusions in children. Two 8-year-old boys had a chief complaint of anterior crossbite. Anterior crossbite correction using a tandem traction bow appliance (TTBA) or a Carriere Motion 3D Class III appliance with a Transforce appliance was planned. By comparing cephalometric radiographs before and after treatment, changes in skeletal growth and incisor inclination to the Frankfort horizontal (FH) plane could be measured. Both devices increased SNA and ANB angles, N-I Pg-A, U1 to SN, and U1 to FH. Both appliances improved facial features and resolution of anterior crossbite. The TTBA and Carriere Motion 3D Class III appliance had similar effects when applied as early treatment for growing mesio-occlusions and anterior crossbite in two boys. However, long-term outcome assessments and well-designed comparative studies are still required.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.535-542
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• 2010

Various difficulties have been increased in the construction of public structure; like the road in the overcrowding urban area, because of civil complaint, cost and period of construction. In oder to overcome these social problems, the tunnel has been planned the road design. Despite the resolution, there are many technical problems when constructed near facilities. The design of new tunnel below the existing service reservoir is applied to the ambient vibration blasting using Plasma. The result of test blasting was exceeded the standard ("2kine"). So it was considered a countermeasure for the vibration reduction applied to change the controlled blasting method, reduce the charge, add the pre middle horizontal hole in the cut blasting site, and so on. The result was satisfied the standard. Accordingly, if the quality of blasting process can be managed well, the application of this alternative method is highly effective one. Also, based on cost analysis between two methods, the alternative method is very competitive.

• Journal of Environmental Science International
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• v.19 no.2
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• pp.171-184
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• 2010

Accurate simulation of the meteorological field is very important to assess the wind resources. Some researchers showed that sea surface temperature (SST) plays a leading role on the local meterological simulation. New Generation Sea Surface Temperature (NGSST), Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA), and Real-Time Global Sea Surface Temperature (RTG SST) have different spatial distribution near the coast and OSTIA shows the best accuracy compared with buoy data in the southeastern coast of the Korean Peninsula. Those SST products are used to initialize the Weather Research and Forecasting (WRF) Model for November 13-23 2008. The simulation of OSTIA shows better result in comparison with NGSST and RTG SST. NGSST shows a large difference with OSTIA in horizontal and vertical wind fields during the weak synoptic condition, but wind power density shows a large difference during strong synoptic condition. RTG SST shows the similar patterns but smaller the magnitude and the extent.