• 한국지구과학회지
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• 제38권3호
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• pp.182-193
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• 2017

A typical snowfall pattern occurs over the east coastal region of the Korean Peninsula, known as the Yeongdong region. The precipitation over the Yeongdong region is influenced by the cold and dry northeasterly wind which advects over warm and moist sea surface of the East Sea of Korea. This study reveals the influence of large-scale factors, affecting local to remote areas, on the mesoscale snowfall system over the Yeongdong region. The National Centers for Environmental Prediction-Department of Energy reanalysis dataset, Extended Reconstructed sea surface temperature, and observed snowfall data are analyzed to reveal the relationship between February snowfall and large-scale factors from 1981 to 2014. The Yeongdong snowfall is associated with the sea level pressure patterns over the Gaema Plateau and North Pacific near the Bering Sea, which is remotely associated to the sea surface temperature (SST) variability over the North Pacific. It is presented that the relationship between the Yeongdong snowfall and large-scale factors is strengthened after 1999 when the central north Pacific has warm anomalous SST. These enhanced relationships explain the atmospheric patterns of recent strong snowfall years (2010, 2011, and 2014). It is suggested that the newly defined index in this study based on related SST variability can be used for a seasonal predictor of the Yeongdong snowfall with 2-month leading.

• 대한전자공학회논문지TC
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• 제41권8호
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• pp.131-137
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• 2004

본 논문에서는 레이더 빔의 이상 전파를 유발시키는 기상 조건을 규명한다. 과대 굴절이나 덕트를 발생시키는 기상 조건의 분석을 위하여 2000년부터 3년간 관측된 한반도의 서해와 남해의 기상 데이터를 이용한다. 고도의 증가에 따른 대기 굴절지수를 계산하고, 굴절 지수가 매우 낮은 고도에서의 기온과 습도의 변화를 고찰한다. 비정상적인 전파에 의한 레이더 에코는 대기 굴절 지수가 -150/km 인 고도에서 나타났으며, 그 고도에서는 급격한 습도의 감소와 함께 기온 역전 현상이 수반되었다.

• 지구물리와물리탐사
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• 제1권3호
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• pp.155-160
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• 1998

확장된 Born 근사법을 사용하는 2.5차원 EM 모델링 알고리듬을 이용하여 2차원 역산에 근거한 EM 토모그래피 기법을 개발하였다. 역산법은 평활화 제한을 가한 감쇠최소자승법을 사용하였으며, 측정값은 2차 자기장의 수직성분으로 제한하였다. 적분방정식법에 근거한 3차원 EM 모델링 프로그램을 이용하여 단순한 형태를 갖는 모형에 대한 이론 자료를 계산하고, 이 자료를 측정값으로 EM 토모피래피 영상을 획득하였다. 거의 모든 경우에 EM 토모그래피 영상은 이상체의 위치는 비교적 정확히 추정하였으나, 전도도는 실제 값보다 상당히 낮게 추정하였다. 해상도 분석결과 수직해상도가 수평해상도에 비하여 월등히 뛰어난 것으로 나타났다.

• 한국환경과학회지
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• 제20권11호
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• pp.1357-1371
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• 2011

Suspended and sinking particles were collected during ODP Leg 119 to the Indian Ocean sector of the Antarctic Ocean. Field work was carried out at four sampling sites in Prydz Bay. Two of these sites were located in the Outer Bay, and two in the Inner Bay. At the four locations, a total of ten deployments of a sediment trap array were made. The concentrations of carotenoids both in suspended and sinking particulate matter in Prydz Bay were analyzed using HPLC. Fucoxanthin was the dominant carotenoid pigments both in suspended and sinking particles. The present study also indicates that 19'-hexanoyoxyfucoxanthin-containing prymesiophytes (Phaeocystis spp.) was abundant in the study area. The flux rates of carotenoids were generally highest at 50 m, and approximately double the flux rates at deeper horizons, however, at Inner Bay sites, the mean flux rates of carotenoids were greatest at 200 m, and 3 times greater than that of 50 m. Such anomalous high fluxes at 200 m imply that grazers were locally abundant between 100 m and 200 m at these sites close to land, and this hypothesis is supported by visual evidence of lots of fecal pellets in the 200 m trap. Integrates standing stocks versus sinking pigments data support that particulate material in Prydz Bay was not recycled rapidly.

• Journal of Chest Surgery
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• 제27권5호
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• pp.353-363
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• 1994

From January 1978 to December 1992, 59 patients of double chambered right ventricle were repaired. Surgical correction consisted of closure of the ventricular septal defect and resection of anomalous muscle bundles through right ventriculotomy [Group I ; 34 patients] or right atriotomy [Group II ; 25 patients]. Between these two groups, there was no difference in the operation time and the postoperative results. All patients survived. In group I, hemodynamically significant residual ventricular septal defect was found in three and reoperations were necessary. In one patient, subacute bacterial endocarditis developed postoperatively. In group II, complete atrioventricular block developed in one and mediastinitis in two. Follow-up period was from 2 to 75 months [mean 17.1 months]. There was no late death. All patients have remained in sinus rhythm except one patient. Careful evaluation of echocardiographic and catheterization data preoperatively and careful examination of the anatomy intraoperatively are necessary so that double chambered right ventricle should not be overlooked, because most ventricular septal defects are now closed through the right atrium. Repair of double chambered right ventricle is also easily performed through the atrial approach. Transatrial repair should be considered as an alternative to the transventricular approach in patients with this congenital heart defect. Successful surgical correction of double chambered right ventricle is expected with excellent long term results.

• 대한원격탐사학회지
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• 제37권1호
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• pp.13-22
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• 2021

The ML 5.8 earthquake shocked Gyeongju, Korea, at 11:32:55 UTC on September 12, 2016. One year later, on the afternoon of November 15, 2017, the ML 5.4 earthquake occurred in Pohang, South Korea. The earthquakes injured many residents, damaged buildings, and affected the economy of Gyeongju and Pohang. The damage proxy maps (DPMs) were generated from Sentinel-1 synthetic aperture radar (SAR) imagery by comparing pre- and co-events interferometric coherences to identify anomalous changes that indicate damaged by the earthquakes. DPMs manage to detect coherence loss in residential and commercial areas in both Gyeongju and Pohang earthquakes. We found that our results show a good correlation with the Korea Meteorological Administration (KMA) report with Modified Mercalli Intensity (MMI) scale values of more than VII (seven). The color scale of Sentinel-1 DPMs indicates an increasingly significant change in the area covered by the pixel, delineating collapsed walls and roofs from the official report. The resulting maps can be used to assess the distribution of seismic damage after the Gyeongju and Pohang earthquakes and can also be used as inventory data of damaged buildings to map seismic vulnerability using machine learning in Gyeongju or Pohang.

• 분석과 대안
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• 제6권1호
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• pp.223-258
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• 2022

The 2018 local elections completely upended the composition of Busan's city council, with the council membership changing from being solidly and consistently conservative to being over 80% liberal. What explains this anomalous outcome? While existing literature suggests the outcome of the 2018 city council elections was the consequence of a combination of structural and strategic factors, such as the decline of regional voting, we argue that the individual-level evaluation of President Moon Jae-in is one of the primary factors driving this result. Although coattails effects are commonly considered in concurrent national legislative elections, the Presidentialized and nationalized politics of Korea makes it possible for Presidential elections to affect local elections as well. We assess our explanation through an analysis of repeated cross-sectional survey data collected just before the 2018 local elections. The results of the analysis show that support for the Democratic Party is very strongly predicted by individual-level evaluation of President Moon. When considered in the context of the timing of presidential and local elections, the results suggest that Presidential coattail effects are capable of destabilizing established political patterns, such as regional voting, if perhaps only in a sporadic and idiosyncratic fashion, depending on whether or not local elections are held early on in a President's term.

• Advances in aircraft and spacecraft science
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• 제9권4호
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• pp.279-300
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• 2022

This paper analyzes the possibilities of a new method to using TLE data for detecting satellite maneuvers. The method has a number of advantages over other methods that are designed to detect maneuvers. It allows not only to detect maneuvers, but also to get a more complete picture of the maneuver. In particular, the method makes it possible to estimate the moments of the beginning and end of the maneuver, calculate the changes in the orbital elements, evaluate the tangential and binormal components of the impulse, and finally, calculate the impulse of the satellite obtained as a result of the maneuver. To demonstrate in detail the capabilities of the algorithm, the proposed method was applied to one of LEO satellites - TIANHUI-1 satellite. After the efficiency of the method was proved, this method was applied to the China Space Station - TIANHE-1 (CSS), Starlink-1095 and Starlink-2305 satellites. The maneuvers of the CSS and Starlink-1095 satellite during their close encounter on 1 July, 2021, and the CSS and Starlink-2305 satellite during their close encounter on 21 October, 2021 are analyzed in detail. The minimum distances between the CSS and Starlink satellites at the moments of their maximum approaches are estimated. An estimate of the computation time of this algorithm is given, and the possibility of its use for monitoring maneuvers or other anomalous orbital changes of a large number of satellites in near real-time is shown. It is assumed that on the basis of this method, a service for monitoring satellite maneuvers can be created.

• Korean Journal of Radiology
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• 제23권2호
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• pp.172-179
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• 2022

Objective: We aimed to evaluate the ostium of right coronary artery of anomalous origin from the left coronary sinus (AORL) with an interarterial course throughout the cardiac cycle on CT and analyze the clinical significance of the ostial findings. Materials and Methods: From January 2011 to December 2015, 68 patients (41 male, 57.3 ± 12.1 years) with AORL with an interarterial course and retrospective cardiac CT data were included. AORL was classified as high or low ostial location based on the pulmonary annulus in the diastolic and systolic phases on cardiac CT. In addition, the height, width, height/width ratio, area, and angle of the ostium were measured in both cardiac phases. After cardiac CT, patients were followed until December 31, 2020 for major adverse cardiac events (MACE). Clinical and CT characteristics associated with MACE were explored using Cox regression analysis. Results: During a median follow-up period of 2071 days (interquartile range, 1180.5-2747.3 days), 13 patients experienced MACE (19.1%, 13/68). Seven (10.3%, 7/68) had the ostial location change from high in the diastolic phase to low in the systolic phase. In the univariable analysis, younger age (hazard ratio [HR] = 0.918, p < 0.001), high ostial location (HR = 4.008, p = 0.036), larger height/width ratio (HR = 5.621, p = 0.049), and smaller ostial angle (HR = 0.846, p = 0.048) in the systolic phase were significant predictors of MACE. In multivariable cox regression analysis, younger age (adjusted HR = 0.917, p = 0.002) and high ostial location in the systolic phase (adjusted HR = 4.345, p = 0.026) were independent predictors of MACE. Conclusion: The ostial location of AORL with an interarterial course can change during the cardiac cycle, and high ostial location in the systolic phase was an independent predictor of MACE.

• 대한영상의학회지
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• 제81권6호
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• pp.1523-1528
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• 2020

부분 폐정맥 환류 이상은 드문 선천성 폐정맥 기형의 한 종류로 진단 시 종종 간과될 수 있다. 대부분의 경우 비 침습적인 영상검사인 심장 초음파, CT 또는 MRI로 진단을 하게 되는데, 2D 모니터를 이용한 영상진단은 삼차원적으로 복잡한 심장의 구조를 이해하는데 제한이 있다. 최근에는 CT와 MRI에서 얻은 의료 영상 데이터를 기반으로 3D 프린팅 기술을 이용하여 심장의 모형을 만드는 기술이 소개되어 점차 이용이 증가되고 있다. 본 증례 보고에서 저자들은 우측 상 폐정맥과 우측 중 폐정맥이 상대정맥으로의 각각 배출되며 우측 중 폐정맥을 통해 양측 심방 간의 연결이 이루어진 환자의 CT 영상 및 3D 프린팅 모델에 대해 보고하고자 한다.