• 천문학회보
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• 제38권2호
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• pp.43.1-43.1
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• 2013

We report the preliminary results of our GMVA(Global mm VLBI Array) observation at the frequency of 86 GHz. Observation were made in the dual polarization mode (LCP and RCP), to produce the polarimetric maps with the maximum angular resolution which the array is capable of. We aim to link the source-integrated AGN polarization properties with the polarized spatial source structure, by mapping the polarized "fine structure" of the target AGN. We selected 2 targets, 0954+658 and 0716+714, which (1) have been observed multiple times by the PdBI polarimetric monitoring program; (2) have sufficient integrated fluxes ($S_{90GHz}$ > 1 Jy) ; (3) are close enough to resolve the source structure < 1 pc with given angular resolution ; and (4) are located at high northern declination for good UV coverages. As preliminary results, we present LL and RR polarized images of each target with the maximum angular resolution of ${\sim}60{\mu}as$. Extended structures, probably the jet outflows, are discovered in both sources.

• 대한인간공학회지
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• 제18권3호
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• pp.13-26
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• 1999

126 male and 95 female Korean college students were examined for Scoliosis by using Moire type body observation apparatus. Scoliotic hump measuring instrument, and spinal cord side curvature condition measuring instrument. The prevalence rate of Scoliosis along with identifying its possible causal factors and characteristics were investigated. The results revealed that 5.56% of male and 8.42% of female students(male to female ratio 1:1.47) were suspected as having Scoliosis. There was a significant correlation between the students who have symptoms of Scoliosis and their physiological measurements(e.g., lower breathing capacity of the lungs). There were also close relationships between the suspected cases and their habits(e.g., poor sitting and sleeping posture). It is concluded that the Scoliosis in Korean college students should not be ignored.

• 한국세라믹학회지
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• 제27권5호
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• pp.652-660
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• 1990

Oxidation of Mn-Zn ferrite was made in air at various temperatures ranging from 400$^{\circ}C$ to 1150$^{\circ}C$. Subsequent reduction fo these oxidized samples was also made in air at 1300-1350$^{\circ}C$ where the spinel phase of Mn-Zn ferrite is stable. Morphological observation revealed that the shape of precipitated hematite was plate or lath type on the close-packed habit plane of {111} ferrite which has a definite orientation relationship. The growth of precipitates showed the behavior fo parabolic dependence of the oxidating time. An apparent activation energy for the growth was found to be 125${\pm}$3Kcal/mol. The fact that pores are observed along the precipitates illustrates the oxidation to occur dominantly by the counterdiffusion of cations and ction vacancies. For the reductio reaction pores are found to form at the site once occupied by the precipitates and at the surface. This observation illustrates that the oxygen volitalization from interior region to the surface is the dominant process for the reduction reaction.

• 천문학회지
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• 제37권5호
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• pp.381-385
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• 2004

Similarly to other cluster of galaxies previously classified as cooling flow systems, the Chandra observation of MKW 3s reveals that this object has a complex X-ray structure hosting both a X-ray cavity and a X-ray filament. Unlike the other clusters, however, the temperature map of the core of MKW 3s shows the presence of extended regions of gas heated above the radially averaged gas temperature at any radius. As the cluster does not show evidences for ongoing major mergers Mazzotta et al. suggest a connection between the heated gas and the activity of the central AGN. Nevertheless, due to the lack of high quality radio maps, this interpretation was controversial. In this paper we present the results of two new radio observations of MKW 3s at 1.28 GHz and 604 MHz obtained at the GMRT. Together with the Chandra observation and a separate VLA observation at 327 MHz from Young, we show unequivocal evidences for a close connection between the heated gas region and the AGN activity and we briefly summarize possible implications.

• Ocean and Polar Research
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• 제24권3호
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• pp.237-247
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• 2002

We report all sky camera and Fabry-Perot interferometer (FPI) observations of mesospheric gravity waves and a 12-hour wave at Resolute $(75^{\circ}N)$ and a joint observation of 10-hour wave with Eureka $(80^{\circ}N)$. All sky camera observations showed a low occurrence of mesosphere gravity waves during equinoxes, which is similar to the mid-latitude region. A slightly higher occurrence near solstice appears to indicate that gravity waves are not filtered out by the neutral wind in the winter. The FPI observation of a 12-hour wave showed amplitude variations from day to day. The phase of the wave is mostly stable and consistent with the GSWM prediction in the winter. The phase shifts with season as predicted by the GSWM. Four events of the 12-hour wave were found in spring with amplitudes larger than the GSW predictions. The FPls at Resolute and Eureka also observed a wave with period close to 10 hours. The 10-hour wave maybe the result of the non-linear interaction between the semi-diurnal tide and the quasi-two day wave. Further studies are under way. Overall, the combined Resolute and Eureka observation have revealed some new fractures about the mesospheric gravity wave, tidal wave, and other oscillations.

• 한국환경과학회지
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• 제23권4호
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• pp.585-594
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• 2014

This study Analyzed four of seven runoffs which had happened in 2012 in comparison with the runoffs shown in Kalesto data, using the fixed surface image velocimetry (FSIV) installed at Oedo stream, Jeju Island. As a result of identifying a runoff curve graph, it was analyzed that the flood runoffs calculated with two observation devices were almost equivalent. As the differences in peak flows were 10 $m^3/s$, 0.7 $m^3/s$ and 3 $m^3/s$, the very similar result values were calculated. Even though there were errors in RMSE(Root Mean Square Error) made by two observation devices according to the degree of the peak flow, the values of $R^2$ by flood event were 0.89, 0.87, 0.86 and 0.82, showing the result values almost close to 1. Therefore, there was a very high correlation in flood runoffs calculated with two observation devices. This research method was considered to be a very suitable method to measure unexpected flood runoffs which could happen in the island area such as Jeju island during bad weather.

• 한국농공학회논문집
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• 제64권6호
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• pp.13-23
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• 2022

The purpose of this study was to analyze the impact of greenhouse cultivation area and groundwater level changes due to the water curtain cultivation in the greenhouse complexes, which are mainly situated along rivers where water resources are easy to secure. The groundwater observation network in Miryang, Gyeongsangnam-do, located downstream of the Nakdong River, was selected for the study area. We classified the groundwater monitoring well into the greenhouse (riverside) and field cultivation areas (plain and mountain) to compare the groundwater impact of water curtain cultivation in the greenhouse complex. The characteristics of groundwater level changes classified by terrain type were analyzed using the observed data. Riverside wells have significant permeability coefficients and are close to rivers, so they are greatly affected by river flow and precipitation changes so that water level shows a specific pattern of annual changes. Most plain wells do not show a constant annual change, but observation wells near small rivers and small-scale greenhouse cultivation areas sometimes show annual and daily changes in which the water level drops during winter. Compared to other observation wells, mountain wells do not show significant yearly changes in water level and show general characteristics of bedrock aquifer well with a low permeability coefficient.

• Journal of Korean Neurosurgical Society
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• 제54권5호
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• pp.431-433
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• 2013

Acute subdural hematoma is usually a neurological emergency that requires hematoma evacuation or close observation. However, spontaneous resolutions of an acute subdural hematoma without surgical interventions have been reported rarely. We report on a case who showed rapid resolution of an acute subdural hematoma with neurological improvement and review the relevant literatures.

• Journal of Chest Surgery
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• 제24권1호
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• pp.88-92
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• 1991

Although there have been diverse opinions, permanent anticoagulation is generally recommended in children with mechanical valves. We experienced the thrombotic dysfunction of mitral St. Jude Medical valve in a 4-year-old child who had been under control of anticoagulation with warfarin sodium. Besides the primary problems related to the prosthetic mechanism, various patient factors might have contributed to the valve thrombosis. We would emphasize the necessity of anticoagulation and the close observation for valve dysfunction in pediatric patients with St. Jude Medical valve in mitral position.

• Journal of Trauma and Injury
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• 제34권3호
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• pp.187-190
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• 2021

A 91-year-old female presented to Chonnam National University Hospital Regional Trauma Center with a lateral compression type III fracture of the pelvis. She was managed non-operatively for a week in the intensive care unit under close observation and had an emergency operation due to delayed onset of an acute obstructed direct inguinal hernia. Traumatic abdominal wall hernias are rare. However, trauma surgeons should always be aware of the possibility of such injuries because of their critical consequences.