• Journal of Astronomy and Space Sciences
• /
• 제5권2호
• /
• pp.97-109
• /
• 1988

The photometric behaviour of XY U Ma, an eclipsing binary showing photospheric and chromospheric activity, has been described by spot hypothesis. They are based on the all the available UBV light curves, which were carried out by Geyer since 1955. A "spherical rectangular" spot model shows very pronounced spot activities during the last 30 years. On the average, the spot covered about 16% of the visible hemisphere. Observational evidence for photospheric and chromospheric activities on the XY UMa and related systems are also discussed.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2002년도 봄 학술발표회 논문집
• /
• pp.725-730
• /
• 2002

The areas around the Nam-Hae are mostly covered in thick soft clay deposits(50∼60.0m). In order to improve the ground in these areas verticals trains have been partially penetrated up to the depth of about 25.0m. However, since the predicted values of settlement have often been changed at some predicted time. Finite element analysis was performed to investigate the consolidation behaviour for it. The results from FEM was compared with various observational methods.

• 한국지구과학회지
• /
• 제25권7호
• /
• pp.586-594
• /
• 2004

이 연구는 야외 지질 학습에 대한 관찰 및 가설을 분석하여 야외 지질 학습에 대한 방향을 찾아보고자 하는 기초 연구의 성격을 가진 질적 연구이다. 야외 지질 학습장에서의 학습 내용을 분석함으로써 관찰, 가설의 관련성을 연구하는데 그 목적이 있다. 이 연구를 통해 얻은 결론은 다음과 같다. 첫째, 지질학습의 특성상 초등학생들은 대부분 시각에 의존하여 관찰하며, 퇴적 지층 지역의 관찰은 암석 관찰에, 가설은 지질 구조에 관한 가설을 많이 생성하였다. 둘째, 관찰 분류들로 분석 한 결과, 이 연구에서 추가한 관찰 행동 영역인 비교 관찰의 빈도가 높게 나타났으며, 2가지 관찰 행동의 조합으로 나타난 사례의 빈도도 높았다. 셋째, 관찰 유형을 기준으로 보면 해석적 관찰 및 비교 관찰과 조합된 과학적 설명 가설의 비율이 가장 높게 나타났다. 이것은 암석과 지질 구조를 해석하고 다른 것과 비교하여 자신의 사고를 합리화 하려는 경향으로 볼 수 있다. 가설 유형을 기준으로 분석한 결과 과학적 설명 가설이 가장 많은 비율을 차지하였고, 사전 지식이나 선개념을 적용하여 해석하고 설명하려는 경향이 있다고 판단된다.

• 한국환경과학회지
• /
• 제17권2호
• /
• pp.195-201
• /
• 2008

Damage from typhoon disaster can be mitigated by grasping and dealing with the damage promptly for the regions in typhoon track. What is this work, a technique to analyzed dangerousness of typhoon should be presupposed. This study estimated 10 m level wind speed using 700 hPa wind by typhoon, referring to GPS dropwindsonde study of Franklin(2003). For 700 hPa wind, 30 km resolution data of Regional Data Assimilation Prediction System(RDAPS) were used. For roughness length in estimating wind of 10 m level, landuse data of USGS are employed. For 10 m level wind speed of Typhoon Rusa in 2002, we sampled AWS site of $7.4{\sim}30km$ distant from typhoon center and compare them with observational data. The results show that the 10 m level wind speed is the estimation of maximum wind speed which can appear in surface by typhoon and it cannot be compared with general hourly observational data. Wind load on domestic buildings relies on probability distributions of extreme wind speed. Hence, calculated 10 m level wind speed is useful for estimating the damage structure from typhoon.

• Journal of the korean society of oceanography
• /
• 제39권1호
• /
• pp.72-95
• /
• 2004

The Yellow Sea is characterized by relatively shallow water depth, varying range of tidal action and very complex coastal geometry such as islands, bays, peninsulas, tidal flats, shoals etc. The dynamic system is controlled by tides, regional winds, river discharge, and interaction with the Kuroshio. The circulation, water mass properties and their variability in the Yellow Sea are very complicated and still far from clear understanding. In this study, an effort to improve our understanding the dynamic feature of the Yellow Sea system was conducted using numerical simulation with the ROMS model, applying climatologic forcing such as winds, heat flux and fresh water precipitation. The inter-annual variability of general circulation and thermohaline structure throughout the year has been obtained, which has been compared with observational data sets. The simulated horizontal distribution and vertical cross-sectional structures of temperature and salinity show a good agreement with the observational data indicating significantly the water masses such as Yellow Sea Warm Water, Yellow Sea Bottom Cold Water, Changjiang River Diluted Water and other sporadically observed coastal waters around the Yellow Sea. The tidal effects on circulation and dynamic features such as coastal tidal fronts and coastal mixing are predominant in the Yellow Sea. Hence the tidal effects on those dynamic features are dealt in the accompanying paper (Kim et at., 2004). The ROMS model adopts curvilinear grid with horizontal resolution of 35 km and 20 vertical grid spacing confirming to relatively realistic bottom topography. The model was initialized with the LEVITUS climatologic data and forced by the monthly mean air-sea fluxes of momentum, heat and fresh water derived from COADS. On the open boundaries, climatological temperature and salinity are nudged every 20 days for data assimilation to stabilize the modeling implementation. This study demonstrates a Yellow Sea version of Atlantic Basin experiment conducted by Haidvogel et al. (2000) experiment that the ROMS simulates the dynamic variability of temperature, salinity, and velocity fields in the ocean. However the present study has been improved to deal with the large river system, open boundary nudging process and further with combination of the tidal forcing that is a significant feature in the Yellow Sea.

• Journal of Microbiology and Biotechnology
• /
• 제25권7호
• /
• pp.1163-1169
• /
• 2015

Poly-gamma-glutamic acid (γ-PGA) is a natural polymer that is synthesized by Bacillus species and has been reported to have antitumor activity. The aim of this study was to investigate the effect of γ-PGA on the treatment of vaginal intraepithelial neoplasia (VAIN). A retrospective observational study on γ-PGA therapy for biopsy-proven VAIN was conducted. The efficacy was assessed by evaluating the results of Pap cytology and the viral load of high-risk HPV at three time points: at enrollment, and at the first and second post-treatment visits. Of 17 patients treated with γ-PGA, only 12 patients who had a high-risk HPV infection were included in the analysis. Histology was VAIN1 in seven patients, VAIN2 in two patients, and VAIN3 in three patients. γ-PGA was administered for newly diagnosed VAIN in five (41.7%) patients and persistent VAIN in seven (58.3%) patients for the mean time of 4.5 months. At the first and second post-treatment visits, cytological regression was observed in five (41.7%) and six (50%) patients, respectively. Regarding the HPV load, the overall response rate was 66.7%, and the mean level was 670.6 ± 292.5 RLU at the first follow-up, which was lower than the initial viral load of 1,494.8 ± 434.5 RLU (p = 0.084). At the second follow-up, the overall response rate was 58.3%, and the mean viral load level was 924.2 ± 493.7 RLU. γ-PGA may be helpful for the cytological regression and reduction of viral load in patients with high-risk HPV-positive VAIN, suggesting that γ-PGA is a promising treatment option for primary or persistent VAIN.

• 대한한방내과학회지
• /
• 제34권2호
• /
• pp.192-203
• /
• 2013

Objectives : To investigate the incidence of drug-induced liver injury (DILI) by combined-prescription of Korean herbal medicine (KHM; prescribed herbal medicine by doctors of traditional Korean medicine) and Western medicine on liver function. Methods : Sixty-nine in-patients who took KHM and Western medicine for various conditions were enrolled for prospective observational study. All subjects were given liver and renal function tests at the start of hospitalization to establish a baseline. After taking KHM and Western medicine, tests were done at approximately 4-week intervals afterwards. Results : Fifty-three subjects showed normal liver function test (LFT) at baseline, 50 subjects (72.5%) remained within the normal range at the second test, while 3 subjects (4.3%) tests revealed slight increase of LFT. However not a single patient had a high enough raised LFT to indicate liver injury. Sixteen of 69 subjects had abnormal baseline, 11 subjects recovered to normal levels and 5 subjects remained at abnormal level. Among all subjects, there was no statistically significant increase in LFT level between the first and second tests. Conclusions : This study shows that the combined-prescription of KHM and Western medicine did not cause any DILI. In some cases, combined treatment increased LFT levels but those increases were not high enough to have statistical significance. Additional large scale and systematical studies are required for more conclusive proof and results.

• 대한지구과학교육학회지
• /
• 제5권2호
• /
• pp.139-147
• /
• 2012

The purpose of this study was to explain how extraordinary the scientific technology or our ancestor was from the modern perspective by remodeling the most unique astronomical instrument, So-ganui (小簡儀), developed in the Sejong Period (世宗時代) after being examined with contemporary and the principles of the science and observational technology would be properly understood and measured directly. When measuring the altitude of the sun and azimuth using So-ganui, it was adjusted with the horizontal coordinate system and measured using Jipyeonghwan (地平環), Ipeunhwan (立運環) and Guyhyeong (窺衡). Based such measuring principles, the measurement accuracy proposed using So-ganui are as follows. The remodeled So-ganui produced approximately ${\pm}0.29$ degrees error on average at high altitude while in measuring the azimuth degrees, there was difference of ${\pm}0.35$ degrees. Since the theoretically, the measurement error for So-ganui was ${\pm}0.5$ degrees, the remodeled So-ganui could accurately measure at the high altitude compared to So-ganui from the Sejong period. In the study, So-ganui, which has disappeared, has been remodeled in modern perspective to be used as the educational material to accurately understand the principles of science and measurement technology from the Sejong period. The findings could contribute to raising the reputation in the astronomical observations from the documents from the Sejong period. Furthermore, this study has materialized the celestial and sky our ancestors have viewed with the observational principles of their times, on the computer screen via a webcam, bringing out interest in the traditional science for the students.

• Tuberculosis and Respiratory Diseases
• /
• 제83권4호
• /
• pp.303-311
• /
• 2020

Background: If the duration of mechanical ventilation (MV) is related with the intensive care unit (ICU) readmission must be clarified. The purpose of this study was to elucidate if prolonged MV duration increases ICU readmission rate. Methods: The present observational cohort study analyzed national healthcare claims data from 2006 to 2015. Critically ill patients who received MV in the ICU were classified into five groups according to the MV duration: MV for <7 days, 7-13 days, 14-20 days, 21-27 days, and ≥28 days. The rate and risk of the ICU readmission were estimated according to the MV duration using the unadjusted and adjusted analyses. Results: We found that 12,929 patients had at least one episode of MV in the ICU. There was a significant linear relationship between the MV duration and the ICU readmission (R²=0.85, p=0.025). The total readmission rate was significantly higher as the MV duration is prolonged (MV for <7 days, 13.9%; for 7-13 days, 16.7%; for 14-20 days, 19.4%; for 21-27 days, 20.4%; for ≥28 days, 35.7%; p<0.001). The analyses adjusted by covariables and weighted with the multinomial propensity scores showed similar results. In the adjusted regression analysis with a Cox proportional hazards model, the MV duration was significantly related to the ICU readmission (hazard ratio, 1.058 [95% confidence interval, 1.047-1.069], p<0.001). Conclusion: The rate of readmission to the ICU was significantly higher in patients who received longer durations of the MV in the ICU. In the clinical setting, closer observation of patients discharged from the ICU after prolonged periods of MV is required.

• 당뇨병
• /
• 제19권3호
• /
• pp.135-139
• /
• 2018

The sodium-glucose cotransporter-2 inhibitor (SGLT2i) is a new anti-hyperglycemic agent that have function to concomitantly inhibit the reabsorption of glucose and sodium in the renal proximal convoluting tubule. Recent two cardiovascular outcome trials showed that a lower risk of cardiovascular events with SGLT2i in people with type 2 diabetes. In addition, prior real-world data demonstrated similar SGLT2i effects, but these studies were limited to the United States and Europe. Thus, the CVD-REAL (Comparative Effectiveness of Cardiovascular Outcomes in New Users of Sodium-Glucose Cotransporter-2 Inhibitors) 2 Study was investigated cardiovascular outcomes in those initiated on SGLT2i versus other glucose-lowering drugs (oGLDs) across 6 countries in the Asia Pacific, the Middle East, and North American regions. In Korea, 336,644 episodes of initiation in SGLT2i or oGLD group between September 2014 and December 2016 were identified in Korea National Health Insurance database after propensity score matching. SGLT2i users was associated with a lower risk of all-cause death (hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.67~0.77), hospitalization for heart failure (HHF) (HR, 0.87; 95% CI, 0.82~0.92), all-cause death or HHF (HR, 0.81; 95% CI, 0.78~0.85), myocardial infarction (HR, 0.81; 95% CI, 0.74~0.89), and stroke (HR, 0.82; 95% CI, 0.78~0.86) compared with oGLD users. In conclusion, initiation of SGLT2i had a lower risk of cardiovascular events in people with type 2 diabetes compared with oGLDs.