• Title/Summary/Keyword: EGM

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Extragastric Metastasis of Early Gastric Cancer After Endoscopic Submucosal Dissection With Lymphovascular Invasion and Negative Resected Margins

  • Lee, Han Myung;Kwak, Yoonjin;Chung, Hyunsoo;Kim, Sang Gyun;Cho, Soo-Jeong
    • Journal of Gastric Cancer
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    • v.22 no.4
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    • pp.339-347
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    • 2022
  • Purpose: Lymphovascular invasion is a criterion for non-curative resection in patients who have undergone endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). We aimed to determine the rate of extragastric metastasis (EGM) and identify the predictors of EGM in patients with negative resection margins (R0 resection) and lymphovascular invasion in post-ESD pathology. Materials and Methods: A total of 2,983 patients underwent ESD for EGC. Among them, 110 had a pathology of R0 resection and positive lymphovascular invasion. Patients underwent additional gastrectomy (n=63) or further follow-up without gastrectomy (n=47). Results: The 110 patients were assigned to one of the 3 groups according to ESD indications based on post-ESD pathology. The first group satisfied the absolute indication for ESD (n=18), the second group satisfied the expanded indications for ESD (n=34), and the last group satisfied the beyond indication (n=58). The number of occurrences of EGM in each group was 1 (5.6%), 3 (8.8%), and 3 (5.2%), respectively. The logistic regression analysis adjusted for age, sex, tumor size, and indication for ESD, showed that larger tumor size was associated with EGM (odds ratio, 1.76; 95% confidence interval, 1.00-3.10; P=0.048). In contrast, ESD indication criteria did not affect EGM (P=0.349). Conclusions: Tumor size was the only predictive indicator for EGM in patients who underwent R0 resection and lymphovascular invasion on post-ESD pathology. Even patients with pathology corresponding to the absolute indication criteria of ESD had lymphovascular invasion, which means that they require additional gastrectomy due to the risk of EGM.

Accuracy Analysis of New Geopotential Model using GPS/Levelling Data (GPS/Levelling데이터를 사용한 새로운 지구중력장모델의 정확도 분석)

  • Yun Hong-Sic;Cho Jae-Myoung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.23 no.4
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    • pp.353-358
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    • 2005
  • The purpose of this paper is to evaluate a new geopotential model, EIGEN-CG01C which had been developed from CHAMP and GRACE mission observations and surface gravity data. The accuracy analysis was conducted by comparing the geoidal heights computed from two types of geopotential models (i.e., EIGEN-CG01C and EGM96) with spirit leveled GPS bench mark. To this end, three hundred twenty GPS leveled bench marks are used as bases for the numerical investigation. From the analysis, it was possible to conclude that EIGEN-CG01C was more suitable to upgrade the KGEOID 98 since the results that the EGM96 was slightly biased.

Calculation of Geoidal Height refered to Bessel Ellipsoid From EGM96 Model (EGM96 모델을 이용한 Bessel 지오이드고의 계산)

  • 최경재;최윤수
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.17 no.1
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    • pp.33-39
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    • 1999
  • In order to calculate geoidal height refered to Bessel ellipsoid, methods to translate geoidal heights from a certain coordinate system to an arbitrary system with the corresponding ellipsoid are studied. and geoidal heights refered to Bessel ellipsoid were computed from EGM96 Model refered to GRS80 using iteration method pro-posed in this paper. Transformation parameters between WGS84 and Bessel were calculated using geoidal heights computed from iteration method. The result of coordinate transformation(standard deviation) were 0.009 second in latitude and 0.006 in longitude and 0.393m in orthometric height.

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GPS/Levelling Geoid of the Southern Korean Peninsula

  • Choi, Kwang-Sun;Lee, Jung-Mo
    • International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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    • v.25 no.1
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    • pp.15-22
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    • 1997
  • The GPS/levelling geoid calculated from GPS survey that data at 123 bench marks represents an appropriate regional geoid of the southern Korean peninsula. The GPS/levelling geoid fits best to the geoid calculated from the EGM96 geopotential model of degree and order to 360 with RMS difference 0.176 m. The good agreement of the GPS/levelling geoid with the EGM96 geoid suggests that the bench mark network is well established in Korea and the EGM96 geopotential model well represents the gravity field in the southern Korean peninsula.

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Calaulation of geometric geoidal heights using GPS/leveling data in study area (GPS/leveling 데이터에 의한 기하학적 지오이드고의 산출)

  • 이석배
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2003.10a
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    • pp.27-31
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    • 2003
  • It can be classified in various methods to get the geoidal heights. It can be achieved geometric geoidal heights if we do GPS surveying in leveling point. The aims of this paper are calculation of geometric geoidal heights using GPS/leveling data in study area and evaluation of the global and local geoid models in and around Korean peninsula. For this study, study area was selected in the leveling line from Kunsan to Chonju city and GPS surveying was accomplished in the leveling line. And, also spherical harmonic analysis was made on the three global geopotential models, OSU91A, EGM96, EGM96m under same condition and KOGD2002, Korean gravimetric geoid model was made in this study The results shows that EGM96m is the best model because the differences between geoidal heights of EGM96m and geometric geoidal heights of GPS/Leveling data appear the smallest value among them.

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Calaulation of Geometric Geoidal Heights Using Gps/leveling Data in Study Area (Gps/leveling 데이터에 의한 기하학적 지오이드고의 산출)

  • 이석배;황용진;이재원
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.22 no.1
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    • pp.45-52
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    • 2004
  • It can be classified in various methods to get the geoidal heights. It can be achieved geometric geoidal heights if we do GPS surveying in leveling point. The aims of this paper are calculation of geometric geoidal heights using GPS/leveling data in study area and evaluation of the global and local geoid models in and around Korean peninsula. For this study, study area was selected in the leveling line from Kunsan to Chonju city and GPS surveying was accomplished in the leveling line. And, also spherical harmonic analysis was made on the three global geopotential models, OSU91A, EGM96, EGM96m under same condition. Then the differences were calculated between geometric geoidal heights and geoidal heights of 3 geopotential models, KOGD2002 which was Korean gravimetric geoid model. The results shows that EGM96m is the best model because the differences between geoidal heights of E6M96m and geometric geoidal heights of GPS/Leveling data appear the smallest value among them.

The Research for Practical Use of GPS/Leveling (GPS/Leveling의 실용적 활용 방안에 관한 연구)

  • Park, Byung-Uk;Choi, Yun-Soo;Shin, Sang-Ho
    • Journal of Korean Society for Geospatial Information Science
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    • v.10 no.2 s.20
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    • pp.107-114
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    • 2002
  • This study aimed to estimate accuracy of GPS/Leveling and to present availability of GPS/Leveling in public surveying. For this purpose, we carried out GPS survey for bench marks and control points of Hongsung area. Orthometric heights calculated by two GPS/Leveling methods were compared to reference height. The one is calculated by base of geoid models such as EGM96, OSU91A, KGEOID99, and the other is calculated by network adjustment using fixed point. The results of GPS/Leveling by geoid models show that RMSE of EGM96 is ${\pm}0.061m,\;OSU91A\;{\pm}0.725m,\;KGEOID99\;{\pm}0.598m$. The results of GPS/Leveling by network adjustment show that the best RMSE is ${\pm}0.043m$ in case of using three fixed bench mark, and this method can be used for leveling effectively. GPS/Leveling would be able to apply in forth order public leveling and height determination of public control points.

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Gravity Potential Comparative Analysis around Korean Peninsula by EGM96 and EIGEN-CG01C Models (EGM96와 EIGEN-CG01C 모델에 의한 한반도 주변의 중력포텐셜 비교분석)

  • Yu, Sang-Hoon;Kim, Chang-Hwan;Min, Kyung-Duck
    • 한국지구물리탐사학회:학술대회논문집
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    • 2005.05a
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    • pp.261-266
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    • 2005
  • According to development of satellite geodesy, gravity potential models which have high accuracy and resolution were released. Using the EIGEN-CG01C model based on low orbit satellite data such as CHAMP and GRACE and the EGM96 model, geoid and gravity anomaly were calculated and compared. The study area is located at $123^{\circ}{\sim}132^{\circ}$ E, $33^{\circ}{\sim}43^{\circ}$ including Korea. Comparing two models, very high correlation more than 0.90 in geoid and gravity anomaly was observed, but in amplitude analysis the EIGEN-CG01C model have higher amplitude in high frequency area. Gravity anomaly calculated with both models shows a little difference in North Korea and some coast area of the Yellow sea. Through power spectrum analysis, residual anomaly that can be used in large scale structure or underground resources survey was calculated.

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Development and validation of Everyday Gender Microaggression Scale (일상 속 성차별 경험 척도 개발 및 타당화)

  • Eunha Kim
    • Korean Journal of Culture and Social Issue
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    • v.24 no.4
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    • pp.593-614
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    • 2018
  • By applying the concept of microaggression (subtle and indirect form of discrimination), the aim of this study was to develop and validate the Everyday Gender Microaggression Scale (EGM). For this purpose, based on the results of literature review, surveys, and individual interviews, we developed 17 pilot items. Next, after expert content validation, we administered online survey to 180 adult women and conducted exploratory factor analysis. The result revealed 2 factors, 14 items, and this structure was reconfirmed through confirmatory factor analysis in another sample of 219 adult women. Convergent and concurrent validities were also examined via correlations with measures of sexism, depression, and life satisfaction. We discussed implications, ways to use the EGM, and suggestions for future research.