• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.4
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• pp.325-332
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• 2022

Determination of VLBI IVP (Very Long Baseline Interferometry Invariant Point) position with high accuracy is required to compute local tie vectors between the space geodetic techniques. In general, reflective targets are attached on VLBI antenna and slant distances, horizontal and vertical angles are measured from the pillars. Then, adjustment computation is performed by using the mathematical model which connects measurements and unknown parameters. This indicates that the accuracy of the estimated solutions is affected by the accuracy of the measurements. One of issues in local tie surveying, however, is that the reflective targets are not in favorable condition, that is, the reflective sheet target cannot be perfectly aligned to the instrument perpendicularly. Deviation from the line of sight of an instrument may cause different type of measurement errors. This inherent limitation may lead to incorrect stochastic modeling for the measurements in adjustment computation procedures. In this study, error characteristics by measurement types and pillars are analyzed, respectively. The analysis on the studentized residuals is performed after adjustment computation. The normality of the residuals is tested and then equal variance test between the measurement types are performed. The results show that there are differences in variance according to the measurement types. Differences in variance between distances and angle measurements are observed when F-test is performed for the measurements from each pillar. Therefore, more detailed stochastic modeling is required for optimal solutions, especially in local tie survey.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.22-22
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• 2020

너도개미자리는 석죽과의 다년생 초본류로 낭림산 이북으로부터 백두산까지 분포하며 고지대에 자생한다. 7~10월에 흰색의 꽃이 개화하고 종자는 달걀모양으로 표면은 밋밋하다. 본 연구는 지피용으로 사용할 너도개미자리의 분화재배 시 적정 추비, 차광 및 적심 등의 처리 정도를 알아보고자 수행하였다. 재배방법의 확립을 위하여 유용식물증식센터에서 종자를 분양받아 2019년 4월 19일에 트레이에 파종하여 충북대학교 유리온실에서 육묘한 유묘를 7월 4일에 정식하여 실험재료로 사용하였으며, 9월 24일까지 약 11주 동안 재배하였다. 공통 조건은 비닐 포트 3치(7×7cm)에 원예상토를 충진하고 200구 트레이에 셀당 1립씩 파종하여 생산된 1셀을 정식하였다. 추비, 차광, 적심 등은 무처리로 수행하였다. 추비실험은 hyponex 하이그레이드(N-P-K, 7-10-6)를 0, 500, 1000, 2000mg·L^-1의 농도로 엽면시비 하였고, 차광 실험은 0, 35, 55, 75% 차광막을 이용하였으며, 적심은 무적심과 재배 4주차의 1회적심 처리로 구분하였다. 연구의 결과, 너도개미자리는 추비처리 농도가 증가할수록 생육도 증가하는 경향이었으나, 유의성은 확인할 수 없었다. 유의적인 차이는 없었지만 2000mg·L^-1 처리구에서 지상부 및 지하부의 생체중이 가장 무거운 결과를 보였다. 차광처리 별로는 무차광 조건에서 생육이 왕성한 결과를 보였고, 차광률의 증가는 생육을 점차 억제하는 경향이었다. 개화율도 무차광에서 가장 높았으며, 다음으로 35% 차광 순이었고, 55와 75% 차광에서는 개화가 진행되지 않았다. 너도개미자리에 적심처리는 초장과 측지수의 발생을 억제하였고, 개화도 지연되는 경향을 보였다. 결론적으로 너도개미자리의 지피용 재배시 광이 충분한 에 배치하여 재배하는 것이 효과적이다. 추비는 Hyponex 하이그레이드를 2000mg·L^-1의 농도를 처리하는 것이 생육에 유리하며, 적심은 하지 않는 것이 효과적인 재배방법인 것으로 판단된다.

• Journal of radiological science and technology
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• v.31 no.3
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• pp.249-258
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• 2008

Purpose : Abdominal obesity with visceral fat accumulation have been known to be intimately associated with the development of metabolic syndrome. Therefore, it is important to estimate the precise amount of visceral fat. Ultrasonography has been reported that it is a simple and noninvasive method for visceral fat evaluation. Purpose of this study is to evaluate the association of ultrasonographic visceral fat thickness, anthropometric indexes, and risk factor of metabolic syndrome, and to investigate the cut-off value of abdominal visceral fat thickness leading to increased risk of metabolic syndrome. Materials and methods : The subject included 200 men and 200 women who visited D healthcare center in Daejeon from January to April 2008. The subcutaneous fat thickness and visceral fat thickness were measured by ultrasonograph. As anthropometric index, we measured body mass index, waist circumference and waist/height ratio. As for the risk factor of metabolic syndrome, we measured blood pressure, high density lipoprotein cholesterol, triglyceride and fasting serum glucose. Results : VFT was significantly correlated with waist circumference, (r=0.683/M, r=0.604/F), waist to height ratio (r=0.633/M, r=0.593/F) and BMI (r=0.621/M, r=0.534/F) in both men and women. In addition it was significantly correlated with Systolic blood pressure (r=0.229/M, r=0.232/F), Diastolic blood pressure ((r=0.285/M, r=0.254/F), high density cholesterol (r=-0.254/M, r=-0.254/F), Triglyceride (r=0.475/M, r=0.411/F), and Fasting blood sugar (r=0.158/M, r=0.234/F) in both men and women. The cut-off value of visceral fat thickness leading to the increased risk of metabolic syndrome was 4.58cm (sensitivity89.2%, specificity 71.2%) in men and 3.50cm (sensitivity61.2% specificity 80.8%) in women respectively. The odds ratio of the risk of metabolic syndrome was dramatically increased with the abdominal visceral fat thickness level over 6cm in men and 5cm in women. Conclusion : The visceral fat thickness using ultrasonography was significantly correlated with anthropometric indexes and risk factors of metabolic syndrome in both men and women. The cut-off value of visceral fat thickness leading to the increased risk of metabolic syndrome was 4.58cm in men and 3.50cm in women.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.344-353
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• 2020

Plants native in Korea have not only ornamental values but also have excellent environmental adaptability, so they can be used as garden plants. Studies on proper volumetric water content (VWC) of substrates have been reported, but many have been conducted in glasshouse conditions where environmental factors were controlled. When considering garden planting, it is necessary to perform the automated irrigation system in outdoor conditions where rainfall occurs at frequent intervals. This research aimed to investigate the VWC suitable for the growth of Minuartia laricina, Arenaria juncea, and Corydalis speciosa in open filed. Sandy soil which consisted of particles of weathered rock was used, and the VWC of 0.15, 0.20, 0.25, and 0.30 ㎥·m^-3 was maintained using an automated irrigation system with capacitance soil moisture sensors and a data logger. No significant differences in growth and antioxidant enzymes activity of A. juncea were observed among VWC treatments. However, the survival rate was low at VWC 0.30 ㎥·m^-3 treatment, which was the highest soil moisture content. Even considering the efficiency of water use, we recommended that VWC 0.15-0.20 ㎥·m^-3 is suitable for the cultivation of A. juncea. Minuartia laricina showed better growth with lower VWC. Because of frequent rainfall in open field, plant volume and survival rate was high even in VWC 0.15 ㎥·m^-3 treatment. In C. speciosa, the plant height, number of shoots and lateral shoots, and fresh and dry weight were higher in plants grown in VWC 0.25 ㎥·m^-3 as compared with that in the plants grown at 0.15, 0.20, and 0.30 ㎥·m^-3. Based on these results, M. laricina needed less water in open filed, and A. juncea and C. speciosa required higher VWC, but excessive water should be avoided.

• Economic and Environmental Geology
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• v.48 no.6
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• pp.451-465
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• 2015

The free-air anomalies are computed using a data set from various types of gravity measurements in the Korean Peninsula area. The gravity values extracted from the Earth Gravitational Model 2008 are used in the surrounding region. The upward continuation technique suggested by Dragomir is used in the computation of the external free-air anomalies at various altitudes. The integration radius 10 times the altitude is used in order to keep the accuracy of results and computational resources. The direct geodesic formula developed by Bowring is employed in integration. At the 1-km altitude, the free-air anomalies vary from -41.315 to 189.327 mgal with the standard deviation of 22.612 mgal. At the 3-km altitude, they vary from -36.478 to 156.209 mgal with the standard deviation of 20.641 mgal. At the 1,000-km altitude, they vary from 3.170 to 5.864 mgal with the standard deviation of 0.670 mgal. The predicted free-air anomalies at 3-km altitude are compared to the published free-air anomalies reduced from the airborne gravity measurements at the same altitude. The rms difference is 3.88 mgal. Considering the reported 2.21-mgal airborne gravity cross-over accuracy, this rms difference is not serious. Possible causes in the difference appear to be external free-air anomaly simulation errors in this work and/or the gravity reduction errors of the other. The external gravity field is predicted by adding the external free-air anomaly to the normal gravity computed using the closed form formula for the gravity above and below the surface of the ellipsoid. The predicted external gravity field in this work is expected to reasonably present the real external gravity field. This work seems to be the first structured research on the external free-air anomaly in the Korean Peninsula area, and the external gravity field can be used to improve the accuracy of the inertial navigation system.

• Journal of Bio-Environment Control
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• v.13 no.1
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• pp.26-32
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• 2004

Growth and yield of cucumber (Cucumis sativus L.) with arch training method were evaluated on several training heights, planting densities, and topping node orders. Cucumber cultivar 'Eunsung-baekdadagi' was planted on 9 June with three training heights of 1.5, 1.8, and 2.1 m, there planting densities of 90${\times}$40, 90${\times}$50, and 90${\times}$60 cm, and five topping node orders of 20th, 30th, 35th, and nontopping. The plot of 2.1 m training height resulted in the higher sun-scald fruit rates due to the higher temperature above 37$^{\circ}C$ in the upper space of plastic house. The plot of 1.8 m arch training height showed higher fruit setting and marketable yield rate compared to the other training heights. The maketable yield rate with 1.8 m height arch training was 102,691 kg ${\cdot}$ $ha^{-1}$, 21% higher value than that of 1.5 m. Powdery mildew incidence increased with the increase of planting density. Lower LAI were shown depending on the higher topping node order. Lower light transmission ratio was shown in the higher planting density plots, might be due to the crowded stems and leaves inside those plots. Fruit setting rate was also higher in main stems rather than in lateral ones. Marketable yie이 in 90${\times}$50 cm planting distance with 35th node topping treatment was 98,311 kg ${\cdot}$ $ha^{-1}$, 5% higher than that 90${\times}$40 cm planting distance with 30th node topping treatment. Thus the 1.8 m of training height, 90${\times}$50 cm of planting distance, and 35th node topping was evaluated for the effective cultivation condition in arch training of cucumber in highland.