• Title/Summary/Keyword: Datum Level

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A Study on the Tidal Harmonic Analysis, and long-term Sea Level Ocillations at Incheon Bay (인천만의 조석조화해석 및 장기해수면 변동연구)

  • Lee, Yong-Chang
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.5
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    • pp.505-513
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    • 2010
  • This study investigate the characteristics of tidal constituents, and long-term mean sea level oscillations at Incheon bay. For this, the conditions of three tide stations around Incheon bay have examined, and carried out harmonic analysis on water level data for periods of about 40 years(1960~2007). Four major tidal constituents($M_2$, $S_2$, $K_1$, $O_1$) of each tide station showed tendency that change over the 18.61year lunar node cycle, and the type of tide at three stations is mainly semi-diurnal tides. And also, the past monthly tidal modulations are especially sensitive to the cumulative year of water level data in accuracy of tidal prediction. In case that regard the detached data at three tide stations as a single time series data of 40 years, the results of analysis on a single time series, long-term mean sea level oscillations and modulations of tidal datum at tide stations appears with a range of about 10cm, respectively. In addition, the predicted tides at the Inchcon harbor by global and regional tide models of OSU(Oregon State University) based on various satellite altimetric(Topex Poseidon, Topex Tandem, ERS, GFO) data are compared with the observed tides by KHOA(the Korea Hydrographic and Oceanographic Administration). The results show that the high resolution regional model is a quite good agreement at coastal shallow water region.

Construction of Sea-Floor Topographic Survey System Based on Echosounder and GNSS (Echosounder와 GNSS 기반 해저지형측량시스템의 구축)

  • Jin-Duk LEE;Yong-Jin CHOI;Jae-Bin LEE
    • Journal of the Korean Association of Geographic Information Studies
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    • v.26 no.1
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    • pp.56-68
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    • 2023
  • A system that extracts seabed topographic information by simultaneously and continuously observing the horizontal position and water depth in the sea by combining a single beam echosounder and GNSS was constructed. By applying the developed system to actual measurements of small-scale sea areas, the effectiveness of bathymetry and sea-floor topographic data acquisition using GNSS and echosounder was examined. By using the developed outdoor program DS-NAV and indoor program DS-CAD and applying the tide level data at the time of actual measurement of the target sea area, it was possible to derive bathymetry results based on the datum level i.e. approximate lowest low water level(A.L.L.W). By using the developed outdoor program DS-NAV and indoor program DS-CAD and applying the tide level data at the time of actual measurement of the target sea area, it was possible to derive the results of bathymetric survey based on the datum level. From database built through the actual measurement. it was possible to create 3D model of the sea-floor topography and extract cross-sections. The results of this study are expected to be economically useful for extracting seabed topographical information from small sea areas or in dredging sites for offshore construction.

Integrated Geospatial Information Construction of Ocean and Terrain Using Multibeam Echo Sounder Data and Airborne Lidar Data (항공 Lidar와 멀티빔 음향측심 자료를 이용한 해상과 육상의 통합 지형공간정보 구축)

  • Lee, Jae-One;Choi, Hye-Won;Yun, Bu-Yeol;Park, Chi-Young
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.4
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    • pp.28-39
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    • 2014
  • Several studies have been performed globally on the construction of integrated systems that are available for the integrated use of 3D geographic information on terrain and oceans. Research on 3D geographic modeling is also facilitated by the application of Lidar surveying, which enables the highly accurate realization of 3D geographic information for a wide area of land. In addition, a few marine research organizations have been conducting investigations and surveying diverse ocean information for building and applying MGIS(Marine Geographic Information System). However, the construction of integrated geographic information systems for both terrain and oceans has certain limitations resulting from the inconsistency in reference systems and datum levels between two data. Therefore, in this investigation, integrated geospatial information has been realized by using a combined topographical map, after matching the reference systems and datum levels by integration of airborne Lidar data and multi-beam echo sounder data. To verify the accuracy of the integrated geospatial information data, ten randomly selected samples from study areas were selected and analyzed. The results show that the 10 analyzed data samples have an RMSE of 0.46m, which meets the IHO standard(0.5m) for depth accuracy of hydrographic surveys.

A Study of the Development of Apartment's Structural Cost Saving Checklist through the Case Research (사례분석을 통한 공동주택 골조공사의 원가절감 체크리스트 개발에 관한 연구)

  • Lee, Kyeong-Seob;Suh, Sang-Wook
    • Korean Journal of Construction Engineering and Management
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    • v.11 no.6
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    • pp.65-77
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    • 2010
  • Our nation's housing construction is given much weight over 32% in 2007 and especially apartment is taking over 67%. If we put into construction environment consideration, we are having a trouble with price cap policy and the realestate recession due to the global economic crisis. So in order to get competitive power and supply of cheap apartment, the necessity of cost saving is increasing. This research collected the past constructed apartment project's cost saving examples which were influencing on the construction cost, quality and time. We analyzed collected cost saving datum and assorted these in compliance with classification system. By analysis of correlation among datum with exclusion and integration, we make a propose cost saving Checklist that will be a base data to give a chance to use in working level and other research.

울릉분지 돌고래 시추공의 생층서: 고환경 및 이들의 석유탐사에의 응용

  • 이성숙;윤혜수;배부영;박세진;이의형;강소라;김재호;김기현
    • 한국석유지질학회:학술대회논문집
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    • autumn
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    • pp.50-67
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    • 1999
  • Biostratigraphic and paleoenvironmental analyses are carried out on cutting samples from the Dolgorae wells drilled in the Ulleung basin. The clayey, silty, and sandy sediments of the wells yield various microfossil assemblages of relatively good preservation, among which five fossil groups are reported; a total of 97 foraminiferal species of 66 genera, 19 nannofossil species of 12 genera, 86 ostracod species of 41 genera, 107 diatom species of 44 genera, and 124 dinoflagellate cysts species of 45 genera. Based on microfossils the geologic ages of the Dolgorae wells are dated to be from late Early Miocene to Early Pleistocene. Several biohorizons are defined in Neogene successions by the LOD (Last Ocurrence Datum) and FOD (First Ocurrence Datum) of marker species including G. truncatulinoides (LOD: 1.9 Ma) of foraminifera; C. macintyeri (LOD: 1.64-1.60), G. oceanica (FOD: 1.65 Ma), G. caribbeanica (1.72 Ma), D. brouweri (LOD: 2 Ma), R. pseudoumbilica (LOD: 3.66 Ma), P. lacunosa (FOD: 4.2 Ma) of nannofossils; S. ellipsoideus (LOD: 4 Ma), S. palcacantha (LOD: 10.2), C. giusepei (LOD: 14 Ma) of dinocysts; D. seminae v. fossilis (FOD: 3.7 Ma), T. antiqua (LOD: 1.7 Ma), T. convexa (LOD: 2.4 Ma), N. kamtschatica (LOD: 2.58 Ma), T. oestrupii(FOD: 5.1 Ma) of diatoms. Abundance patterns of microfossils throughout the wells reflect changes in paleoenvironmental and sedimentological settings of the basin in relation to sea-level variations. According to these data the large-cycle and small-cycle changes of transgression and regression phases are observed in terrestrial to marine sediments. This high-resolution sequence biostratigraphy established by various fossil groups enabled more reliable correlation between strata and refined interpretation on deposition systems of the basin. It also proved to provide fundamental and precise informations regarding stratigraphic correlation, tectonic events, basin, and depositional history for hydrocarbon explorations, especially in collaboration with seismic-stratigrahic analyses.

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The View Character of Mountainscape of a City according to Visual Point Level - In a Case of Mt. Uam - (시가지내 산악경관의 시점 높이별 조망 특성 - 청주시 우암산을 대상으로 -)

  • Jeong, Jeong Seop;Gwon, Sang Jun;Jo, Tae Dong
    • Journal of Environmental Science International
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    • v.13 no.6
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    • pp.497-503
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    • 2004
  • In this research, we have performed a T-test to see how the relationship between dependent variable or visual point level and independent variable or visual quantity is in order to clear up the correlation between pattern of visual point and visual quantity by the constituents of a view from a different visual point level and the results are as follows: 1) In case of the character of Mt. Uam landscape of the city, Uamsan is set as a fixed point and about a direction of view(D), the north is a datum point from which the range of direction is distributed within 1800 westwardly and the visual range(R) is also within 2000m. An elevation is an average of 7.40 and the average story of the buildings is 3.85. Here the height of a story is about 4m so the average of the visual point difference is estimated at 15.4m. 2) The type of visual point is divided into the intersection group and the front of the highly used public buildings group. Double intersection types account for about 78.80%(52 spots) which forms a majority part of LCP. 3) The analysis of the difference of visual point level divided by eye level and that of the top of the buildings has been proved that there's a sharp difference resulted from t-test at 1 % significant level. The significant difference of elevation from height difference(l5.93m), however, has not been shown. 4) From the result of T-test about visual quantity by the elements of a view from a different visual point level, the visual quantity of mountain(VQM), sky(VQS), ground(VQG) is significant at about 1% each and that of building(VQB) is at about 5%. The difference in visual quantity of a mountain by the visual point level is at about 4% which can meet a marginal level of LCP necessary for evaluation of mountainscape.

The Study of Coastal Change from Using Ortho Aerial Photo and Hydrographic Survey : the Parcel under the Sea (정사항공사진과 해양조사측량을 이용한 해안선변화탐지에 관한 연구 : 포락지 중심으로)

  • Choi, Chul-Eung;Seo, Yeong-Chan;Yang, Ji-Yeon;Park, So-Yeong;Kim, Youn-Soo
    • 한국지형공간정보학회:학술대회논문집
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    • 2004.10a
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    • pp.167-173
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    • 2004
  • The erosion(or sediment) reaches very serious level due to the aftermath by the imprudent reclamation on the coast. Continuous studies for long on coastline erosion may be warranted and possible countermeasures proposed because the change of the coastline has been progressed slowly for a long period of time in a wide area. Many experts anticipate that the global sea level's average increase by 19-35 cm due to global warming may certainly have an effect on the coastal erosion throughout the world. Thus, a more rigorous study on the causes of changing coastlines is particularly proposed to find ways to counteract any possible threats against coastal environments. In this study, Ortho aerial photo and hydrographic survey datum were utilized to quantitatively analyze coastal erosion and sediment patterns. This paper also seeks to prove that a parcel under the sea occurred due to relatively significant changes to the coastline. We created Ortho aerial photo using aerial photos taken each decade ('81, '93, '00), overlaid them onto a cadastral registration map, and calculated each amount of erosion and sediment while accounting for the tide level and without considering it. As the result of this study, we could propose that the methods of Ortho aerial photo and the marine observation datum were the effective ways of change detection in erosion, sediment, and artificial reclamation of the coastline for a long time.

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A Study of Damage District Forecast by Combine Topograph Modeling of Insular Areas Using GIS

  • Choi, Byoung Gil;Na, Young Woo;Ahn, Soon Myoung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.2
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    • pp.113-122
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    • 2017
  • Natural disasters caused by climate change are increasing globally. There are few studies on the quantitative analysis methods for predicting damages in the island area due to sea level rise. Therefore, it is necessary to study the damage prediction analysis method using the GIS which can quantitatively analyze. In this paper, we analyze the cause and status of sea level rise, quantify the vulnerability index, establish an integrated terrestrial modeling method of the ocean and land, and establish a method of analyzing the damage area and damage scale due to sea level rise using GIS and the method of making the damage prediction figure was studied. In order to extract the other affected areas to sea level rise are apart of the terrain model is generated by one requires a terrain modeling of target areas are offshore and vertical reference system differences in land, found the need for correction by a tidal observations and geoid model there was. Grading of terrain, coastline erosion rate, coastal slope, sea level rise rate, and even average by vulnerable factors due to sea level rise indicates that quantitative damage prediction is possible due to sea level rise in the island area. In the case of vulnerable areas extracted by GIS, residential areas and living areas are concentrated on the coastal area due to the nature of the book area, and field survey shows that coastal changes and erosion are caused by sea level rise or tsunami.

Preliminary Study of Vertical Datum Determination in Korea (수직기준 결정을 위한 기초 연구)

  • Jeong, Tae-Jun;Yun, Hong-Sic;Huang, He
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.55-58
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    • 2007
  • This study describes a problem of the Original Bench Mark which is used currently. We calculate New Mean Sea Level(MSL) in Incheon Port using tide data for 57 months and take 8 points GPS/Leveling data in research area. We calculate orthometric height of one control point using tide data and GPS/Leveling data. After fixed the control point, we decide final orthometric heights using relative geoidal height and ellipsoidal height from GPS survey. To analysis the Original Bench Mark compares final orthometric heights with the orthometric heights in Korea height system. We get the result that the New Original Bench Mark's height is 26.7176m. It appears 3.05cm difference as the Original Bench Mark's height is 26.6871cm in Korea height system.

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A Study on Disagreement of Family Finances and Related variables (가계의 재정불일치 및 관련 변인에 관한 연구)

  • 정선희;오정옥
    • Journal of Families and Better Life
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    • v.9 no.2
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    • pp.19-35
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    • 1991
  • The Purpose of this study is to search a tendency of financial disagreement and to identify the variables influencing on financial disagreement of husbands and wives. for this purpose, reviewing literatures and empirical research were conducted. The sample was selected from the husbands and wives living in Masan, Changwon and Jinhae. Among 336 respondents. 111 husbands and 225 wives were finally selected as datum sources. The data were analyzed by the statistical method such as frequency distribution percentile ,ANOVA. Peason's correlation and Regression analysis. The main results were as follows; 1) Most husbands and wives showed th high level of financial disagreements. 2) As for the related variables, socio-demographic and psychological variables such as husband's education. family income, communication and financial management behavior had turned out to be significant on the financial disagreement of wives. As for the husband's financial disagreement, husband's education and family income had a significant influence. 3) There were negative correlation between the financial management behavior and the financial disagreement of husbands and wives(r=-0.22. -0.35). 4) the family characteristics which were the best predictors of financial disagreement included; family income, financial management behaviro of husbands and wives.

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