• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.4
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• pp.393-403
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• 2011

In this study, we suggested the period of tide observations is proper to calculate the mean sea level(MSL) precisely on Incheon tide station using wavelet analysis, and newly determined then the vertical reference surface of Korea using the calculated MSL. In order to calculate the height difference between the calculated MSL and specific ground station (ICGP) near the Incheon tide stations, we performed the laser measurements directly to the sea surface where located below ICGP. The orthometric-height of ICGP was determined that corrected the height difference to the calculated MSL using linear interpolation method. Finally, we connected the orthometric-height of ICGP with the original benchmark (ORBM) using GPS leveling methods for determining the new orthometric-height of ORBM. As the results, there is a variation amount of 0.026m between the new MSL was calculated in this study and old MSL was calculated in 1910's. Also, there is a difference of 0.035m between the new and old orthometric-heights of ORBM. The connection (or leveling) error of 0.009m was revealed in new orthometric height of ORBM with consideration of MSL variation which may caused by the error of GPS ellipsoid height and/or geoid model. In this study, we could be determined precisely the orthometric-height of ORBM based on the new MSL of Incheon Bay using only GPS leveling method, not a spirit leveling method. Therefore, it is necessary to determine the vertical datum strictly using long-term and continuously tide observations more than 19 years and to use the GPS leveling method widely in the height leveling work for the effective changeover from the orthonormal to the orthometric in national height system.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.06a
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• pp.405-410
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• 2008

세계적으로 세계측지좌표계의 도입이 확대됨에 따라 우리나라도 2001년 측량법의 개정을 통해 현재의 지리정보 좌표계변환을 위한 노력을 시행하고 있다. 이러한 측면에서 본 연구에서는 세계측지좌표계 변환방법론, 변환사례 등을 검토 후 한국토지정보시스템 데이터를 대상으로 시범지역을 선정하여 변환실험을 실시하였다. 그 결과 변환 후의 데이터는 국가GIS활용 및 업무지원을 위한 참조적 데이터로서 충분히 이용이 가능한 수준으로 도출되었다. 하지만 한국토지정보시스템 데이터의 세계측지좌표계로의 변환을 위해서는 각 지역별 변환계수를 산정할 필요가 있으며, 지적데이터가 가지고 있는 다양한 원점을 통일원점으로 변환되어야 할 것으로 판단된다. 또한 마지막으로, 기존의 지적데이터가 가지는 다양한 문제점을 그대로 내포하는 수준으로 변환되었다. 따라서 한국토지정보시스템의 세계측지좌표계 변환을 위해서는 본 연구의 결과를 기초로 하여, 더 많은 대상지역에 대한 변환을 통해 오차와 오류의 유형별 원인 분석 후 한국토지정보시스템의 세계측지좌표계 변환의 체계적이고 계획적인 전략을 수립할 필요가 있다.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.06a
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• pp.281-282
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• 2010

우리나라의 수직기준은 인천만의 평균해수면으로 이 높이를 기준으로 수준점의 표고를 결정한다. 현재 우리나라 수준점의 고시성과는 실제 중력의 영향을 고려하는 대신 정규중력식에 의한 타원보정량을 계산하여, 높이차를 보정한 뒤 수준원점을 고정하고 최소제곱법을 수행하여 산출한 정규표고이다. 하지만 우리나라의 경우 산지가 많아 지형의 기복이 심하고 산맥을 가로지르는 수준노선이 있어 중력에 의한 영향을 무시할 수 없으나 현재 그 영향을 고려하고 있지 못하고 있는 실정이다. 따라서 본 연구에서는 항공 중력데이터를 이용하여 수준점의 중력값을 산출한 뒤 정표고를 산출하여 현재 사용하고 있는 고시좌표와 비교해 보고자한다.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.1
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• pp.51-61
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• 2019

Computing the sea level slope at the BM(Bench Mark) in the coast areas around the Korean Peninsula is important for establishing height of BM of the Korean geodetic leveling network. In this study, MSL(Mean Sea Level) was recalculated with the long-term tide observation data based on the IHO(International Hydrographic Organization) standard(18.6 years), and the BM height was reanalyzed by precision leveling. The sea surface topography was analyzed by leveling at Mokpo(Mokpo Starting Point), Busan (09-00-00) and Mukho(20-26-00) BMs, and the sea level slope was computed based on the Korean vertical origin point. As a result of this study, the sea level slope of the west and east coasts between Incheon(-2.27cm) and Mukho(17.56cm) located at $37.5^{\circ}N$ was analyzed as 19.83cm. Domestic geodesists and oceanologists have confronted each other with regard to the issue of latitudinal changes in long term MSL. In the west coast, the Mokpo is 1.12cm higher than Incheon, and the Busan is 2.18cm higher than Mukho. Therefore, the west and east coasts have been analyzed as sea level slope rising to the south. It can be used to solve the reestablishment of the Korean geodetic leveling network and the problem of the elevation discrepancy in the BM.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.7 no.2
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• pp.1-6
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• 1989

The adjustment of levelling net is being done to the order of nets independently by using the least square method. For the small size net, it has difficulties in verification and statistical analysis of the net since the degree of freedom is low At the same time, it is also difficult to evaluate the error of lower order net correctly. The aim of this study is to analyse the properties of combined adjustment method compared with the independent adjustment method by using the data which have been measured during 1967-1987. Another aim is to analyse the influences of normal orthometric correction and changes of datum. Finally, Korean leveling net has been evaluated by applying real redundancy and variance component estimation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.1
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• pp.99-106
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• 2010

A vertical datum requires an origin, which is a point on the Earth's surface where the height of the point is a defined value(26.6871m). From this origin point, heights (height differences) can be measured to any other point using standard leveling and gravity measurement procedures. However, the leveling network over the Korea bas been established by using the normal gravity instead of the actual gravity values, and the heights for the points are published by National Geographic Information Institute (NGII). This may cause height for especially in the area where high-relief mountains are dominant. Therefore, the height errors caused by using normal gravity instead of actual gravity values are analyzed in this study. Then, the differences between the orthometric heights and the published heights, i.e., normal orthometric height are analyzed.

• 한국사회정책
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• v.25 no.1
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• pp.321-343
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• 2018

This paper aims to apply the convergence theory into the minimum income guarantee which forms the moral foundation of the welfare state. The research question of this paper is if the level of minimum income guarantee among EU member states (EU-15) gradually converging into a certain level. For this purpose, Chapter 2 describes the convergence and diversion of welfare states since the Second World War, and chapter 3 explains the historical development of the EU social policies since the Rome Treaty (1957). Chapter 4, which is the main body of this paper, analyzes if the level of minimum income guarantees of EU member states is converging by the coefficient of variation analysis and regression analysis. However, converging trend of the level of basic income guarantee among EU member states has not been proved. In other words, social policy arena still remains strongly in the realm of national sovereign states, irrespective of growing pressure from the supra-national governing body like the EU. It is in line with the Abram de Swaan's argument that "welfare states is nation states" (1994: 110).

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.11a
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• pp.49-52
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• 2011

본 논문에서는 구간선형 모델을 적용하여 낮은 복잡도를 가지는 LSC(Lens-Shading Correction) 알고리즘을 제안한다. 제안한 알고리즘은 각 화소와 렌즈 중심점으로부터 거리를 정수형으로 계산하고, 이 정수를 거리에 대한 LSC 이득값이 저장된 LUT(Look-Up Table)에 대한 주소로 적용하여, 입력 화소 값에 곱함으로써 LSC를 수행한다. 거리를 구하려면 제곱근 회로가 추가되어야 한다. LUT에 저장된 이득값은 원점으로부터의 거리에 대한 평균 이득값을 저장하고 있기 때문에, 제곱근 계산에 높은 정밀도를 할애하여도 LSC 보상된 영상의 화질에 미치는 영향은 높지 않으므로 정수형 제곱근 연산을 수행한다. 제곱근 계산은 구간 선형화하여 단지 덧셈과 쉬프트 연산만으로 제곱근 연산을 완료할 수 있도록 간략화 하였다. 제안한 알고리즘을 양산 중인 일반 카메라 모듈에 적용한 결과, 카메라모듈 제조업체의 LSC 평가 기준을 상회하는 수준으로 나타나며, 구현될 하드웨어 복잡도가 매우 낮아서 모바일 카메라 구현에 매우 적합하다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.1
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• pp.17-26
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• 2008

The 1st order level network of Korea was adjusted simultaneously in 1987. After that, the 1 st order level network of Korea was adjusted simultaneously by National Geographic Information Institute in 2006. The levelling data were acquired by digital level with invar staff from 2001 through 2006. The 1st order level network consists of 36 level lines. Among them, 34 level lines comprise 11 level loops. Among 36 level lines, 4 level lines have fore & back error larger than the regulations for the 1st order levelling of NGII, Korea. Also, the closing error of 3 loops of level network exceed the regulation for the 1st order levelling of NGII. The standard error of fore and back leveling between bench marks(${\eta}_1$) are distributed between 0.2 $mm/{\surd}km$ and 1.7 $mm/{\surd}km$. The standard error of loop closing(${\eta}_2$) is 2.0 $mm/{\surd}km$. This result means that the 1st order level network of Korea qualifies for the high precision leveling defined by International Geodetic Association in 1948. As the result of the 1st order level network adjustment, the reference standard error($\hat{{\sigma}_0}$) of the level network was 1.8 $mm/{\surd}km$, which is twice as good as that of the 1st adjustment of level networks in 1987.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.431-440
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• 2017

This study surveyed pre-service early childhood teachers' level of concern about software education on the assumption that software education will be introduced into early childhood education in the future. It was shown that the pre-service early childhood teachers' level of concern about software education is the highest at stage 0(95%) and that they have a high level of informative, personal and managerial concern. Thus, a non-user pattern was mostly indicated. However, compared to the typical non-user pattern, their personal and informative level of concern is slightly higher. A 'tailing up' phenomenon to stage 6(refocusing) was shown. Hence, a pattern aspect close to critical non-user appeared to some extent. A difference in the significant level of concern was shown at all stages, except for managerial concern, according to the need for awareness, the appearance of a future implementation plan, and technology efficacy level. Based on this outcome, it was proposed that teacher training in early childhood software education should be made available as part of the educational activity connected with the Nuri Curriculum, since this would be more suitable for young children's developmental level than the early childhood software education, including coding education, etc., currently found in private institutions.