• Journal of Chest Surgery
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• v.50 no.5
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• pp.363-370
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• 2017

Background: Extracorporeal life support (ECLS) is widely used in refractory heart or lung failure, and the demand for inter-facility transportation on ECLS is expanding. However, little is known about post-transportation outcomes, the clinical safety of such transportation, or the characteristics of the transported patients. Methods: This was a retrospective review of a 3-year, single-institution experience with inter-facility ECLS transport, as well as a comparative analysis of clinical outcomes with those of in-house patients. We also analyzed the risk factors for hospital mortality in the entire ECLS population using univariate and multivariate analyses to investigate the effects of transport. Results: All 44 patients were safely transported without adverse events. The average travel distance was 178.7 km, with an average travel time of 74.0 minutes. Early survival of the transported group seemed to be better than that of the in-house group, but the difference was not statistically significant (70.5% vs. 56.6%, p=0.096). The incidence of complications was similar between the 2 groups, except for critical limb ischemia, which was significantly more common in the transported group than in the in-house group (25.0% vs. 8.1%, p=0.017). After adjusting for confounders, being part of the transported group was not a predictor of early death (adjusted odds ratio, 0.689; p=0.397). Conclusion: Transportation of patients on ECLS is relatively safe, and the clinical outcomes of transported patients are comparable to those of in-house ECLS patients. Although matched studies are required, our study demonstrates that transporting patients on ECLS did not increase their risk of hospital mortality after adjustment for other factors.

• The Journal of the Petrological Society of Korea
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• v.6 no.1
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• pp.19-33
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• 1997

This study reports the results about the petrography and geochemical characteristics of 10 representative volacanic rocks. The Cretaceous volcanic rocks distributed in the vicinity of the Kageo island composed of andesitic rocks, dacitic welded tuff, and rhyolitic rocks in ascending order. Sedimentary rock is the basement in the study area covered with volcanic rocks. Andesitic rocks composed of pyroclastic volcanic breccia, lithic lapilli tuff and cryptocrystallin lava-flow. Most dacitic rocks are lapilli ash-flow welded tuff. Rhyolitic rocks consists of rhyolite tuff and rhyolite lava flow. Rhyolite tuff are lithic crystal ash-flow tuff and crystal vitric ash-flow tuff with somewhat accidental fragments of andesitic rocks, but dacitic rocks. The variation of major and trace element of the volcanic rocks show that contents of $Al_2O_3$, FeO, CaO, MgO, $TiO_2$ decrease with increasing of $SiO_2$. On the basis of Variation diagrams such as $Al_2O_3$ vs. CaO, Th/Yb vs. Ta/Yb, and $Ce_N/YB_N$ vs. $Ce_N$, these rocks represent mainly differentiation trend of calc-alkaline rock series. On the discriminant diagrams such as Ba/La and La/Th ratio, Rb vs. Y + Nb, the volcanic rocks in study area belongs to high-K Orogenic suites, with abundances of trace element and ternary diagram of K, Na, Ca. According to the tectonic discriminant diagram by Wood, these rocks falls into the diestructructive continental margin. K-Ar ages of whole rocks are from andesite to rhyolite $97.0{\pm}6.8~94.5{\pm}6.6,\68.9{\pm}4.8,\61.5{\pm}4.9~60.7{\pm}4.2$ Ma, repectively. Volcanic rocks in study area show well correlation to the Yucheon Group in terms of rock age dating and geochemcial data, and derived from andesitic calc-alkaline magma that undergone low pressure fractional crystallization dominated plagioclase at <30km.

• Journal of Astronomy and Space Sciences
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• v.28 no.3
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• pp.203-216
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• 2011

To prepare for a future Korean lunar orbiter mission, semi-optimal lunar capture orbits using finite thrust are designed and analyzed. Finite burn delta-V losses during lunar capture sequence are also analyzed by comparing those with values derived with impulsive thrusts in previous research. To design a hypothetical lunar capture sequence, two different intermediate capture orbits having orbital periods of about 12 hours and 3.5 hours are assumed, and final mission operation orbit around the Moon is assumed to be 100 km altitude with 90 degree of inclination. For the performance of the on-board thruster, three different performances (150 N with $I_{sp}$ of 200 seconds, 300 N with $I_{sp}$ of 250 seconds, 450 N with $I_{sp}$ of 300 seconds) are assumed, to provide a broad range of estimates of delta-V losses. As expected, it is found that the finite burn-arc sweeps almost symmetric orbital portions with respect to the perilune vector to minimize the delta-Vs required to achieve the final orbit. In addition, a difference of up to about 2% delta-V can occur during the lunar capture sequences with the use of assumed engine configurations, compared to scenarios with impulsive thrust. However, these delta-V losses will differ for every assumed lunar explorer's on-board thrust capability. Therefore, at the early stage of mission planning, careful consideration must be made while estimating mission budgets, particularly if the preliminary mission studies were assumed using impulsive thrust. The results provided in this paper are expected to lead to further progress in the design field of Korea's lunar orbiter mission, particularly the lunar capture sequences using finite thrust.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.3
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• pp.237-246
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• 2000

An experimental study has been carried out using a rotating water channel in order to investigate the effect of surface roughness on the vertical dispersion of plume within boundary layer. Dispersion measurements of tracers released from two sources with different height at neutral conditions over various rough terrain ranging from rural to urban have been performed. Various values of roughness length were simulated by combining of 4 stream velocities and 3 roughness element conditions. Dispersion measurements have also been made for rough terrain where high buildings are locally concentrated. Values of $\sigma$z increase with roughness and this tendency appears to apply both cases of with and without locally concentrated high buildings. The comparisons of the Bowne's nomogram on $\sigma$2 vs x relationship and the measurements of $\sigma$2 with roughness show good accordance in $\sigma$2 distribution at stability D class over rural, suburban and urban terrain. For constant roughness length the $\sigma$2 values of plumes from lower source height are smaller than those of plumes from higher source at short downwind distance, but this relationship becomes reverse as distance increases. Crossing appears to be made before about 2km. The value of constant I in McMullen's equation $\sigma$2=exp [I+J(In x) + K(In x)2] appears to increase with roughness length, however, the relationships between other constants and roughness have been confirmed. The values of $\sigma$2 for various downwind distances, estimated by using an equation which is employed in ISC (Industrial Source Complex) dispersion model for areas where high buildings are locally assembled, are in accordance with measurements from water channel experiments.

• KCID journal
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• v.18 no.2
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• pp.87-100
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• 2011

This study is to delineate the watershed hydrological parameters such as area, slope, rain gauge weight, NRCS-CN and time of concentration (Tc) by using the Geographic Information Sytem (GIS) technique, and estimation of design flood for an ungauged watershed. Especially, we attempted to determine the Tc of ungauged watershed and develop simple program using the cell-based algorithm to calculates upstream or downstream flow time along a flow path for each cell. For a $19km^2$ watershed of tributary of Nakdong river (Seupmoon), the parameters including flow direction, flow accumulation, watershed boundary, stream network and Tc map were extracted from 30m Agreeburn DEM (Digital Elevation Model) and landcover map. And NRCS-CN was extracted from 30m landcover map and soil map. Design rainfall estimation for two rainfall gauge which are Sunsan and Jangcheon using FARD2006 that developed by National Institute for Disaster Prevention (NIDP). Using the parameters as input data of HEC-l model, the design flood was estimated by applying Clark unit hydrograph method. The results showed that the design flood of 50 year frequency of this study was $8m^3/sec$ less than that of the previous fundamental plan in 1994. The value difference came from the different application of watershed parameter, different rainfall distribution (Huff quartile vs. Mononobe) and critical durations. We could infer that the GIS-based parameter preparation is more reasonable than the previous hand-made extraction of watershed parameters.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.79-79
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• 2010

To investigate whether the present-day active galaxies follow the same black hole mass vs. stellar velocity dispersion (MBH-$\sigma*$) relation as quiescent galaxies, we measured the velocity dispersions of a sample of local Seyfert 1 galaxies, for which black hole masses were measured via reverberation mapping. We measured stellar velocity dispersions from high S/N optical spectra centered on the Ca II triplet region (${\sim}8500^{\circ}A$), obtained at the Keck, Palomar, and Lick Observatories. For two objects, in which the Ca II triplet region was contaminated by nuclear emission, we used high-quality H-band spectra obtained with the OH-Suppressing Infrared Imaging Spectrograph and laser-guide star adaptive optics at the Keck-II Telescope. Combining our new measurements with data from the literature, we assemble a sample of 24 active galaxies with stellar velocity dispersions and reverberation MBH in the range of black hole mass 106< MBH /$M{\odot}$ < 109,toobtainthefirstreverberationmappingconstraintsontheslopeandintrinsicscatteroftheMBH- $\sigma*$ relation of active galaxies. Assuming a constant virial coefficient f for the reverberation MBH, we find a slope ${\beta}=3.55{\pm}0.60$ and the intrinsic scatter ${\sigma}int=0.43{\pm}0.08$ dex in the relation log (MBH/M${\odot}$)=$\alpha+\beta$ log(${\sigma}*$/200 km s-1), which are consistent with those found for quiescent galaxies. We derive an updated value of the virial coefficient f by finding the value which places the reverberation masses in best agreement with the MBH - $\sigma*$ relation of quiescent galaxies; using the quiescent MBH - $\sigma*$ relation determined by Gultekin et al. we find log f=0.72+0.09 (or $0.71{\pm}0.10$) with an intrinsic scatter of $0.44{\pm}0.07$ (or 0.46+0.07) dex. No correlations between f and parameters connected to the physics of accretion (such as the Eddington ratio or line-shape measurements) are found. The uncertainty of the virial coefficient remains one of the main sources of the uncertainty in black hole mass determination using reverberation mapping, and therefore also in single-epoch spectroscopic estimates of black hole masses in active galaxies.

• Atmosphere
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• v.21 no.3
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• pp.229-241
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• 2011

The continuous urbanizations by a rapid economic growth and a steady increase in population are expected to have a possible impact on meteorology in the downwind region. Long-term (1972~2007) trends of precipitation have been examined in the mid-Korean peninsula for the westerly condition only, along with the sensitivity simulations for a golden day (11 February 2009). During the long-term period, both precipitation amount (PA) and frequency (PF) in the downwind region (Chuncheon, Wonju, Hongcheon) of urban area significantly increased for the westerly and light precipitation ($PA{\leq}1mm\;d^{-1}$) cases, whereas PA and PF in the mountainous region (Daegwallyeong) decreased. The enhancement ratio of PA and PF for the downwind region vs. urban region remarkably increased, which implies a possible urbanization effect on downwind precipitation. In addition, the WRF simulation applied for one golden day demonstrates enhanced updraft and its associated convergence in the downwind area (about 60 km), leading to an increase in the cloud mixing ratio. The sensitivity experiments with the change in surface roughness demonstrates a slight increase in cloud water mixing ratio but a negligible effect on precipitation in the upwind region, whereas those with the change in heat source represents the distinctive convergence and its associated updraft in the downwind region but a decrease in liquid water, which may be attributable to the evaporation of cloud droplet by atmospheric heating induced by an increase in an anthropogenic heat. In spite of limitations in the observation-based analysis and one-day simulation, the current result could provide an evidence of the effect of urbanization on the light precipitation in the downwind region.

• Journal of Korean Neurosurgical Society
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• v.56 no.1
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• pp.42-47
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• 2014

Objective : Helicopter ambulance transport (HAT) is a highly resource-intensive facility that is a well-established part of the trauma transport system in many developed countries. Here, we review the benefit of HAT for neurosurgical patients in Korea. Methods : This retrospective study followed neurotrauma patients who were transferred by HAT to a single emergency trauma center over a period of 2 years. The clinical benefits of HAT were measured according to the necessity of emergency surgical intervention and the differences in the time taken to transport patients by ground ambulance transport (GAT) and HAT. Results : Ninety-nine patients were transferred to a single university hospital using HAT, of whom 32 were taken to the neurosurgery department. Of these 32 patients, 10 (31.3%) needed neurosurgical intervention, 14 (43.8%) needed non-neurosurgical intervention, 3 (9.4%) required both, and 11 (34.4%) did not require any intervention. The transfer time was faster using HAT than the estimated time needed for GAT, although for a relatively close distance (<50 km) without ground obstacles (mountain or sea) HAT did not improve transfer time. The cost comparison showed that HAT was more expensive than GAT (3,292,000 vs. 84,000 KRW, p<0.001). Conclusion : In this Korean-based study, we found that HAT has a clinical benefit for neurotrauma cases involving a transfer from a distant site or an isolated area. A more precise triage for using HAT should be considered to prevent overuse of this expensive transport method.

• Proceedings of the International Union of Geodesy And Geophysics Korea Journal of Geophysical Research Conference
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• 2003.05a
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• pp.16-16
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• 2003

본 연구는 ILP(International Lithosphere Project) Task Group II-4가 진행하고 있는 상부맨틀에 대한 3차원 구조도 작성 연구의 일환으로 수행되어졌으며 구조도 작성을 위한 데이터 베이스의 구조는 task group의 표준안을 따랐다. 기존 문헌과 기존의 데이터 베이스를 통해서 획득된 자료를 이용해 동해와 그 주변을 대상으로 하는 지역의 ($32-45^{\circ}$E, $122-148^{\circ}$N) 상부 670km까지의 3차원 구조도 작성을 위한 초기 모델을 구축하였으며, 이 절차를 최대한 자동화하는 프로그램을 포트란을 이용해 만들어보았다. 연구 지역에 대한 곡율을 계산하기 위해 표준타원체 모델인 WGS84과 geoid undulation 모델인 EGM96을 사용했으며 지형 고도 자료는 GTOPO30, GLOBE 1.0, 그리고 Smith and Sandwell 데이터베이스를 사용하여 지구 중심으로부터 지표까지의 거리를 구하였다. 연구지역은 $0.25^{\circ}$간격으로 나누었으며 총 5777개의 격자점을 정의하였으며 각각의 격자점에 1차원 수직구조를 부여함으로써 3차원 모델을 구축하였다. 그리고 지형적으로나 지질학적으로 유사한 지역을 하나의 구역으로 정의하고 동일한 수직구조를 부여함으로써 모든 격자점에 1차원 수직구조를 정의하지 않도록 하였다. 본 연구에서는 지표 지질은 모델에 고려하지 않았지만 지형학적으로 의미가 있는 분지나 수평적으로 불균질성이 뚜렷한 지역을 중심으로 연구 지역의 리젼을 정의하였다. 중요 리젼에 대한 지각구조에 대해서는 기존의 문헌을 통해 모델치를 정의하였으며 지각 하부부터 상부 670km에 대한 부분은 Task Group에서 제시한 표준 모델을 이용했다. 모델을 정의하기 위해 주어진 격자점에 대한 지구 중심으로부터 지오이드까지의 거리, 지오이드로부터 지표까지의 거리를 정의해주었으며, 각 격자점의 수직구조를 정의하기 위해 깊이에 따른 각 매질의 밀도, P파의 속도, S파의 속도, P파에 대한 Q값, S파에 대한 Q값을 정의 해주었다. S파의 속도를 구하기 위해서 지구 내부 물질을 포아송 매질이라는 가정 하에, 관계식을 $Vp{\;}={\;}SQRT(3){\;}{\times}{\;}Vs$ 이용하였다. 획득한 모델치들을 이용해 동해와 동해 인근 지역에 대한 초기모델을 구축하였다.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.4
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• pp.319-325
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• 2015

Among solute carrier proteins, the organic anion transporters (OATs) play an important role for the elimination or reabsorption of endogenous and exogenous negatively charged anionic compounds. Among OATs, SLC22A9 (hOAT7) transports estrone sulfate with high affinity. The net decrease of estrogen, especially in post-menopausal women induces rapid bone loss. The present study was performed to search the SNP within exon regions of SLC22A9 in Korean females with osteoporosis. Fifty healthy controls and 50 osteoporosis patients were screened for the genetic polymorphism in the coding region of SLC22A9 using GC-clamped PCR and denaturing gradient gel electrophoresis (DGGE). Six SNPs were found on the SLC22A9 gene from Korean women with/without osteoporosis. The SNPs were located as follows: two SNPs in the osteoporosis group (A645G and T1277C), three SNPs in the control group (G1449T, C1467T and C1487T) and one SNP in both the osteoporosis and control groups (G767A). The G767A, T1277C and C1487T SNPs result in an amino acid substitution, from synonymous vs nonsynonymous substitution arginine to glutamine (R256Q), phenylalanine to serine (F426S) and proline to leucine (P496L), respectively. The Km values and Vmax of the wild type, R256Q, P496L and F426S were 8.84, 8.87, 9.83 and $12.74{\mu}M$, and 1.97, 1.96, 2.06 and 1.55 pmol/oocyte/h, respectively. The present study demonstrates that the SLC22A9 variant F426S is causing inter-individual variation that is leading to the differences in transport of the steroid sulfate conjugate (estrone sulfate) and, therefore this could be used as a marker for certain disease including osteoporosis.