• 한국해양환경ㆍ에너지학회지
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• 제19권1호
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• pp.62-73
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• 2016

식생/모래기반 자연해빈에서의 파랑, 조석, 강우조건에 의한 지하수위 변동은 식생 환경과 밀접한 관련이 있으며 이는 식생 발달 및 지반 안정화에 크게 영향을 주는 요소이다. 본 연구는 낙동강 하구역의 사주섬 중 최서측에 위치하는 진우도를 대상으로 실험구를 구축한 후 해안선의 법선 방향으로 관측점 5곳을 선정하여 2012년 3월부터 2014년 9월까지(약 799일간) 관측된 수온, 전기전도도, 압력값을 이용하여 지하수위 변동해석을 하였다. 지하수위의 수온, 염분, 수위 변동과 조위, 파랑, 강수량 등의 외력조건과의 시계열 분석 및 상관분석을 통하여, 소상대 정점에서는 파랑 및 조위의 영향, 식생 및 모래지반 정점에서는 강수량 및 조위의 영향을 크게 받음을 알 수 있었다. 고파랑 내습시 관측점간의 지하수위 및 전기전도도의 공간적 거동을 살펴본 결과 Sand dune 및 Vegetation zone이 시작되는 인근에서 담수층과 해수층의 천이 영역(Transition zone)이 존재하였다.

• 천문학회지
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• 제43권4호
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• pp.123-133
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• 2010

In order to study properties of the pulsation in the infrared emission for long period variables, we collect and analyze the infrared observational data at L band for 12 OH/IR. The observation data cover about three decades including recent data from the ISO and Spitzer. We use the Marquardt-Levenberg algorithm to determine the pulsation period and amplitude for each star and compare them with results of previous investigations at infrared and radio bands. We obtain the relationship between the pulsation periods and the amplitudes at L band. Contrary to the results at K band, there is no difference of the trends in the short and long period regions of the period-luminosity relation at L band. This may be due to the molecular absorption effect at K band. The correlations among the L band parameters, IRAS [12-25] colors, and K band parameters may be explained as results of the dust shell parameters affected by the stellar pulsation. The large scatter of the correlation could be due to the existence of a distribution of central stars with various masses and pulsation modes.

• Journal of Astronomy and Space Sciences
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• 제13권1호
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• pp.72-78
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• 1996

복잡한 광도변화를 보이는 RS CVn형 단주기 식쌓성 UV Piscium의 BV 광도곡선을 Wilson-Devinney의 차등보정 방법으로 분석하여 궤도요소들을 산출하였다. 우리가 분석에 사용한 광도곡선은 식이 일어나지 않고 있는 부분에서도 심한 광도변화를 보이고 있는데 이는주성에 흑점 군이 있기때문인 것으로 가정하고 이 흑점군의 위치와 크기 등도 계산하였다. 그 결과 UV Psc는 분리계쌍성이며 주성이 반성에 비하여 질량도 크고 온도도 높으나 반경은 거의 같다는 것을 알았다. 이것은 일반적인 항성 모형과는 대조를 보이는 것이어서 이를 검증하기 위한 관측이 요구된다.

• 천문학논총
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• 제30권2호
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• pp.649-650
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• 2015

We have been performing daily VLBI monitoring of the flux density of Sagittarius (Sgr) $A^{\ast}$ at 22 GHz from February 2013 to August 2014 using a sub-array of the Japanese VLBI Network (JVN). The purpose of this monitoring is to explore the flux density variability at daily time resolution for a period longer than one year with the G2 cloud approaching. The flux density of Sgr $A^{\ast}$ is basically stable during the observational period, though there are some small variations. The average and scattering range are consistent with the previously observed values. We have observed no strong flare of Sgr $A^{\ast}$ although it is near the expected peri-center passing.

• 대한원격탐사학회지
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• 제20권5호
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• pp.307-313
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• 2004

The trajectories of 8 autonomous profiling floats deployed in the Kuroshio Extension region in February 2001 are used to depict the circulation pattern at the surface and 2000db. The corresponding sea surface topography maps created from satellite altimeter and dynamic height climatology were compared with the tracks of nearly coincident floats and were found to agree well in most cases except for the period June 5 to 16 2001. It is shown that over the period the conspicuous breakaway of the floats from an expected path is possibly associated with the abnormal path of the Kuroshio Extension such as an outbreak event, as revealed by AVHRR infrared and SeaWiFS chlorophyll-a images and cruise data in cross sections.

• 천문학회보
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• 제44권1호
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• pp.81.1-81.1
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• 2019

Linear sausage oscillations of a cylinder embedded in a plasma with an azimuthal magnetic field, created by a current on the surface of the cylinder, are studied. Such a plasma configuration could be applied to modelling demonstrate that the lowest radial harmonic of the sausage mode is in the trapped regime for all values of the parallel wave number. In the long-wavelength limit, phase and group speeds of this mode are equal to the Alfven speed in the external medium. It makes the oscillation period to be determined by the ratio of the parallel wavelength, e.g., double the length of an oscillating loop, to the external Alfven speed, allowing for its seismological estimations. The application of the results obtained to the interpretation of long-period (longer than 20-30 s) oscillations of emission intensity detected in solar coronal structure, gives reasonable estimations of the external Alfven speed. Cutoff values of the parallel wavenumber for higher radial harmonics are determined analytically. Implications of this finding to the observational signatures of fast magnetoacoustic wave trains guided by the plasma non-uniformity are discussed.

• Journal of Acupuncture Research
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• 제33권2호
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• pp.11-20
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• 2016

Objectives : The purpose of this study is to investigate the clinical effectiveness of Korean medical combination treatment for cervical disc herniation. Methods : This is an observational study. 102 patients diagnosed with cervical disc herniation by MRI (Magnetic Resonance Imaging) were investigated from January, 2015 through to December, 2015 at Daejeon Jaseng Hospital of Korean Medicine. They were sorted according to the distribution of sex, age, causing factor, the period of disease, admission day and pain area. All patients were treated with acupuncture, Chuna treatment, and herbal therapy and physical therapy during the admission period. After treatment, NRS (Numeric Rating Scale), NDI (Neck Disability Index) and EQ-5D were assessed to evaluate the treatment efficacy. Results : There were more females than Males with a ratio of 1 : 1.37, the age of fifty was the most with 35.29 %, reason unknown was the most with 72.55 % and the subacute stage was the most with 38.24 %. According to disc herniation types, patients with protruded disc types were the most with 66.67 % and a lesion of C5/6 was the most with 41.18 %. For patients diagnosed with cervical disc herniation, neck and shoulder pain NRS decreased from $6.43{\pm}1.77$ to $3.96{\pm}1.96$(p<0.001) and radiating pain NRS decreased from $5.64{\pm}1.96$ to $3.57{\pm}1.88$ (p<0.001). NDI decreased from $41.72{\pm}14.04$ to $30.84{\pm}15.34$(p<0.001), and the EQ-5D index increased from $0.68{\pm}0.17$ to $0.79{\pm}0.14$(p<0.001) after treating cervical disc patients. Conclusion : Korean medical combination treatment might be effective in decreasing pain and raising the life quality of patients with cervical disc herniation.

• 한국응급구조학회지
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• 제24권3호
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• pp.161-169
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• 2020

Purpose: This study aims to identify changes in patients' transport time and chief complaints visiting the emergency room via emergency medical services from the "pre-COVID-19 period" compared to the "COVID-19 early-stage period". Methods: This retrospective observational study analyzed the emergency medical services reports at two time periods defined by the COVID-19 virus outbreak in Korea. The study was conducted in Busan, the Republic of Korea, from January 19 through May 6, 2019. Results: The transfer time of patients transported during the "COVID-19 early-stage period" was significantly delayed compared to the "pre-COVID-19 period" (p<.05). We found a significant increase in transport time for patients complaining of respiratory infections compared to patients without symptoms (p<.05). During the "COVID-19 early-stage period", there was a significant increase in the number of patients with respiratory infections and patients complaining of general symptoms compared to the "COVID-19early-stage period" (p<.05). Conclusion: The spread of the COVID-19 virus infection delayed patient transport and increased the number of patients reporting respiratory infection symptoms. Emergency medical services will need administrative and economic support to transport the increased number of patients requiring services.

• Journal of Korean Neurosurgical Society
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• 제67권2호
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• pp.186-193
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• 2024

Objective : The treatment paradigm for acute ischemic stroke has undergone several major changes in the past decade, contributing to improved patient prognosis in clinical practice. However, the extent to which these changes have affected patient prognosis in the real-world is yet to be clarified. This study aimed to evaluate the real-world impact of modern reperfusion therapy for acute ischemic stroke using data from the National Health Insurance Service in Korea. Methods : This study included patients aged 18-80 years who were admitted via the emergency room with an I63 code between 2011 and 2020. The rates of intravenous thrombolysis use and endovascular treatment according to the year of admission were investigated. Furthermore, the rates of decompressive craniectomy and 3-month mortality were also analyzed. The 10-year observational period was divided into three periods based on the 2015 guideline change as follows : prior, 2011-2014; transitional, 2015-2016; and modern, 2017-2020. Results : A total of 307117 patients (mean age, 65.7±10.9 years) were included, and most patients were male (59.7%). The rate of endovascular treatment gradually increased during the study period from 0.71% in the prior period to 1.32% in the transitional period and finally to 1.85% in the modern period. Meanwhile, the 3-month mortality rate gradually decreased from 4.78% in the prior period to 4.03% in the transitional period and to 3.71% in the modern period. Conclusion : In Korea, the mortality rate decreased as the rate of modern reperfusion therapy increased in patients with acute ischemic stroke. Overall, technical and scientific advances in reperfusion therapy have improved the outcome of patients with acute ischemic stroke in Korea.

• Journal of Astronomy and Space Sciences
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• 제15권2호
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• pp.297-306
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• 1998

Photoelectric observations of the neglected eclipsing binary VZ Cep were made on four night during the observing season of 1984 at Sobaeksan Astronomy Observatory. The UBV light curves were secured incompletely with the gap in 0.35-0.75 phases. From the observations three times of minimum lights were determined in three band-passes, which formed one weighted minimum epoch (JD Hel 2446009.0453). With our observations, and improved light elements for VZ Cep is determined using all the photoelectric and CCD times of minimum lights published so far. The (O-C) resid-uals calculated with our light elements show small varying scatters which cannot be negligible. From the analyses of all the times of minima with the Scargle’s(1982)period-searching and a curve fitting methods, we found possible periodic oscillations of the (O-C) residuals with the period of 1. y26 and the amplitude of 0.d0032. These results, however, have to be considered as a preliminary values until complete analysis for the minimum lights of VZ Cep with enough observational data. Future observations of this binary system are urgently prompted.