• Title/Summary/Keyword: point datum

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A Study on Traffic Accident Analysis Treatment and a plan Practical Use by Photogrammetry (사진측량에 의한 교통사고분석처리 및 활용방안에 관한 연구)

  • 백은기;김감래
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.7 no.1
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    • pp.27-35
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    • 1989
  • Sport photographing by the Stereo-Camera generally used in Europ, Japan, etc was applied to the traffic-accident analysis more preferreatially than the measuring with Tape where some problems are found in its accuracy and duribility. Time for photographing and that for measuring a datum point were compared causes for accidents were analyzed by spot drawing PAMS, with a patameter of an exclusively used drawing set, after 3-dimensions were first measured and computed in Stereo-model. Also the collision-angle, the direction of the handle and the quartity of loss after a clash were computed by using a accident vehicle as a model those data was suggested as a way of potential practical the accidents at large.

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Scheme and application of phase delay spectrum towards spatial stochastic wind fields

  • Yan, Qi;Peng, Yongbo;Li, Jie
    • Wind and Structures
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    • v.16 no.5
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    • pp.433-455
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    • 2013
  • A phase delay spectrum model towards the representation of spatial coherence of stochastic wind fields is proposed. Different from the classical coherence functions used in the spectral representation methods, the model is derived from the comprehensive description of coherence of fluctuating wind speeds and from the thorough analysis of physical accounts of random factors affecting phase delay, building up a consistent mapping between the simulated fluctuating wind speeds and the basic random variables. It thus includes complete probabilistic information of spatial stochastic wind fields. This treatment prompts a ready and succinct scheme for the simulation of fluctuating wind speeds, and provides a new perspective to the accurate assessment of dynamic reliability of wind-induced structures. Numerical investigations and comparative studies indicate that the developed model is of rationality and of applicability which matches well with the measured data at spatial points of wind fields, whereby the phase spectra at defined datum mark and objective point are feasibly obtained using the numerical scheme associated with the starting-time of phase evolution. In conjunction with the stochastic Fourier amplitude spectrum that we developed previously, the time history of fluctuating wind speeds at any spatial points of wind fields can be readily simulated.

The Values and Uses of Korea's Geographic Center as Locational Resource (지리적 위치자원으로서의 국토정중앙의 가치와 활용 방안)

  • Kim, Chang-Hwan
    • Journal of the Korean association of regional geographers
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    • v.14 no.5
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    • pp.453-465
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    • 2008
  • The purpose of this study is to introduce the concept of the geographic center, to examine its value as locational resource, and to consider the way of its practical uses. Geographic center is the intersection point where central meridian and central parallel cross each other. This geographic locational resources can be used as data for locational education in geographic education, the standards for antipodes, datum points for geodetic surveying, a factor of place marketing, etc. This study can be a model for a geographic discovery that is to seek many geographic resources being scattered about our country.

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Digital Bathymetric and Topographic Data for Neighboring Seas of Korea (한국근해의 디지털 수심.표고 데이터베이스)

  • 최병호;김경옥;엄현민
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.14 no.1
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    • pp.41-50
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    • 2002
  • An attempt has been made to establish digital bathymetric and topographic database in the form of grid point value(GPV) with an interval of one-minute horizontal space fur a wide region of seas adjacent to Korean Peninsula and also with an interval of one-arcsecond for coastal seas of Korean Peninsula. Especially terrestrial and marine data fusion work using mean sea level as vertical datum plane has been performed for one-arcsecond GPV dataset. It is believed that the compiled bathymetric dataset are reliable comparing with existing dataset so for and can be utilized for ocean simulations of intermediate scale process and also detailed coastal inundation process.

Potential Accuracy of GNSS PPP- and PPK-derived Heights for Ellipsoidally Referenced Hydrographic Surveys: Experimental Assessment and Results

  • Yun, Seonghyeon;Lee, Hungkyu;Choi, Yunsoo;Ham, Geonwoo
    • Journal of Positioning, Navigation, and Timing
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    • v.6 no.4
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    • pp.211-221
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    • 2017
  • Ellipsodially referenced survey (ERS) is considered as one of the challenging issues in the hydrographic surveys due to the fact that the bathymetric data collected by this technique can be readily transformed either to the geodetic or the chart datum by application of some geoscientific models. Global Navigation Satellite Systems (GNSS) is a preferred technique to determine the ellipsoidal height of a vessel reference point (RP) because it provides cost-effective and unprecedentedly accurate positioning solutions. Especially, the GNSS-derived heights include heave and dynamic draft of a vessel, so as for the reduced bathymetric solutions to be potentially free from these corrections. Although over the last few decades, differential GNSS (DGNSS) has been widely adopted in the bathymetric surveys, it only provides limited accuracy of the vertical component. This technical barrier can be effectively overcome by adopting the so-called GNSS carrier phase (CPH) based techniques, enhancing accuracy of the height solution up to few centimeters. From the positioning algorithm standpoint, the CPH-based techniques are categorized under absolute and relative positioning in post-processing mode; the former is precise point positioning (PPP) correcting errors by the global or regional models, the latter is post-processed kinematic positioning (PPK) that uses the differencing technique to common error sources between two receivers. This study has focused on assessment of achievable accuracy of the ellipsoidal heights obtained from these CPH-based techniques with a view to their applications to hydrographic surveys where project area is, especially, few tens to hundreds kilometers away from the shore. Some field trials have been designed and performed so as to collect GNSS observables on static and kinematic mode. In this paper, details of these tests and processed results are presented and discussed.

An Error Examination of 3D Face Automatic Recognition (3차원 안면자동인식기의 형상복원 오차검사)

  • Suk, Jae-Hwa;Cho, Kyung-Rae;Cho, Yong-Beum;Yoo, Jung-Hee;Kwak, Chang-Kyu;Lee, Soo-Kyung;Kho, Byung-Hee;Kim, Jong-Won;Kim, Kyu-Kon;Lee, Eui-Ju
    • Journal of Sasang Constitutional Medicine
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    • v.18 no.2
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    • pp.41-49
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    • 2006
  • 1. Objectives The Face is an important standard for the classification of Sasang Contitutions. We are developing 3D Face Automatic Recognition Apparatus to analyse the facial characteristics. So We should examine a shape demobilization error of 3D Face Automatic Recognition Apparatus. 2. Methods We compared facial shape data be demobilized by 3D Face Automatic Recognition Apparatus with facial shape data that be demobilized by 3D laser scanner. The subject was two korean men. And We analysed the average error and the maximum error of two data. In this process, We used one datum point(the peak of nose) and two datum line(vertical section and horizontal section). 3. Results and Conclusions In each this comparison, the average error of vertical section was 1.962574mm and 2.703814mm. and the maximum error of vertical section was 16.968249mm and 18.61464mm. the average error of horizontal section was 4.173203mm and 21.487479mm. and the maximum error of horizontal section was 3.571210mm and 17.13255mm. Also We complemented this apparatus a little and We reexamined a shape demobilization error of 3D Face Automatic Recognition Apparatus again. Accuracy of a shape demobilization was improved a little. From now on We complement accuracy of a shape demobilization in 3D Face Recognition Apparatus.

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The Korean Geodetic Network Adjustments for EDM Area (국가기준점 망조정에 관한 연구 - EDM 관측지역)

  • Yang, Hyo-Jin;Choi, Yun-Soo;Kwon, Jay-Hyoun;Kim, Dong-Young
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.25 no.5
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    • pp.393-398
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    • 2007
  • According to the Korean datum change to a world geodetic system, the EDM area should be readjusted to provide consistent product over the country. The data set for EDM area is extracted from the previous KTN1987 DB and checked for the moved markers in XY network adjustment which provides quality verification. Then, EDM data set for the seven areas are rebuilt for the adjustment. Since the data is still based on the old datum, the coordinates of the data are transformed by applying the coordinate transformation parameters. Here, the transformation parameters, which were determined for the conversion of 1:50,000 topographic maps by NGII, were used. For each EDM point, the geoidal height from EGM96 model is applied to obtain the ellipsoidal height based on the GRS80. The measured distance projected onto GRS80 is adjusted using BL network adjustment by fixing 2nd order or 3rd order GPS control points. The results from the readjustment show the minimum standard error of 1.37" and the maximum standard error of 2.13". Considering the measurement accuracy of EDM (1.6" corresponding to about 2cm) and GPS position for fixed points (2cm), this result is considered to be reasonable and it is good for the practical use.

A Study on the Erosion and Retreat of Sea-Cliff through the Multi-temporal Aerial Photograph Data and Field Survey: The Case Study of Taean Peninsula, Korea (다중시기 항공사진과 현장조사를 통한 해안침식 변화 연구: 태안반도를 사례로)

  • WOO, Han-byol;JANG, Dong-Ho
    • Journal of The Geomorphological Association of Korea
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    • v.17 no.4
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    • pp.71-83
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    • 2010
  • In this study, the volume of shoreline retreat at sea-cliffs in the Taean peninsula(West Coast of Korea) was estimated and their erosion and seasonal landforms characteristics changes were investigated through multi-temporal aerial photographs and field survey. Based on the analysis of aerial photographs through ortho-correction, the results show that the length of shoreline and erosion area increase as erosion at sea-cliffs occurs in Pado-li and Dundu-li. To obtain the seasonal quantitative landforms changes and retreat of sea-cliffs, we marked top, middle, and bottom datum-points, from which the distance to the nearest bedrock was repeatedly measured. In these regions, the retreat of sea-cliffs gradually increases in spring to summer, but gradually decreases in autumn. In particular, the typhoon that has a great influence on the Korean peninsula in July to September in summer would drastically increase the retreat of sea-cliffs in comparison with other seasons. As the outcrop of sea-cliffs repeats freezing and thawing in winter, the retreat of sea-cliffs increases a little due to active mechanical weathering. To know the erosion and seasonal landforms changes of sea-cliffs, we took pictures of them in every month and then analyze their condition. The retreat of sea-cliffs was repeatedly occurred by the circulation of the erosion of sea-cliff base, landslides, the formation of slope sediment debris and their erosion, in that order.

The Study of Coastal Change Detection Ortho Aerial Photo and Hydrographic Survey: Parcels Submerged (정사항공사진과 해양조사측량을 이용한 해안선변화 탐지에 관한 연구: 포락지 중심으로)

  • Choi Chul Eung;Kim Youn Soo;Suh Yong Cheol
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.17 no.2
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    • pp.61-69
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    • 2005
  • The coastal erosion and the look of a heap which are mainly occurred in the district along the coast are found for various forms such as the estuary closing, the estuary sand bar the development of the coast sand bar, and the modification of coastline. Recently, due to the coastal development, these transformations have been intensified. The change of coast, which has been made slow progress is required long-term study on a searching examination of the root cause and a suggestion of a counter measure. In this research, ortho aerial photos were produced to analyze volumes of topographical alternations that have been progressed fer the long run, by 10s cycle from 1940s through 1990s, to compute accurate volumes of coastline variation, through a datum point and G.C.P (Ground Control Point). Also in this study, without respect to water level, the coastline variation was analyzed by using comparatively analyzed a Idlest land map, a cadastral map. And to analyze topographical variation volumes, the tidal station's materials was used under consideration f3r tide. Finally, topographical variation volumes are comparatively analyzed through surveying and sounding and a point of fine of aviation photographing was calculated and revised. After this research, by using ortho aerial photos, We can understand efficiency of these in computing volumes of variations of coastline by analyzing quantitatively erosion and look of a heap. Besides, in the future, these will be used for information gathering of the coastline integration control system.

A Study On the Operating Room Nurses' Performances of Duties and Their Fatigue (수술실간호사의 직무수행과 피로에 관한 연구)

  • Park, Jeong Sook
    • Korean Journal of Occupational Health Nursing
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    • v.6 no.2
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    • pp.110-127
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    • 1997
  • The aim of this study is to present the basic datum for the promotion of effectiveness and improvement of nursery tasks, by grasping the situation of operating room nurses tasks and the degree of their fatigue. For these researches, 70 nurses out of the operating rooms of 3 university-affiliated hospitals-two in Seoul and one in Pusan, were chosen at random by a non-probability sampling method. These researches were done from April 14 to April 26 in 1997 by questionairing method. The questionaire was composed of 30 items, which asks the examinees of their physical, mental, and neurosensory symptoms, with 10 items respectively. The reliability of the research instrument was turned out very high with Cronbach's ${\alpha}=.9376$. The datum were electronically processed using Statistics Program for Social Sciences(SPSS). The analysis of datum in this study has a general character, in which the demosociological character and the special ex-officio character was calculated by frequency and percentage. The situation of tasks in operating rooms was calculated by frequency and percentage. The fatigue of operating room nurses was calculated by average and standard deviation. To compare the fatigue with regard to the character of operating room nurse's tasks, t-test and F-test(ANOVA) were used after the character of variations, and the variations at the level of P<.05 which might have some meaning was verified after the fact with Duncan's Multiple Range(DMR). The results of this research are as follows : 1) The nurses working in operating rooms show their fatigue in three fields-in Group I physical symptoms 3.28, in Group III neurosensory symptoms 2.85, and in Group II mental symptoms 2.73, which shows I Dominant type (general type). 2) They complain, in Group I they are "feeling the heavy legs," 3.28 and in Group II they "occasionally forget soon what to do," 3.09. and in Group III, they "feel lumbago," 3.47, which is the highest rate of the three. The highest rate results from the character of their tasks, in which they have to move rapidly the heavy appliances and do their jobs standing many hours, especially wearing heavy radiation protector. 3) As to transportation, subway using group feel the greatest fatigue, 3.18(F=4.315, P=.008). 4) As to department, nurses in the orthopedic's surgery part feel the greatest fatigue, 3.26(F=2.040, P=.050). 5) As to the change of physical symptoms, the group answering that they found physical abnormality after working in operating rooms show the greatest fatigue, 3.12(t=-3.13, P=.003). 6) At to the general circumstances, the group answering that they receive insufficient consideration on their physical abnormality in their department, show the greatest fatigue, 3.10(F=3.200, P=0.47). 7) As to the relation with superior officers, the group answering that their superior officer has an impetuous temperament, show great fatigue, 3.11(F=4.855, P=.011). 8) As to the time of feeling fatigue, the fatigue reaches the highest point 1~2 hours after operations, 3.04(F=2.703, P=.046). 9) When they feel fatigue after scrub nurse duties, they feel the greatest fatigue 2 hours after the duties, 3.09( F=2.841, P=.038). 10) As to the operation instruments, when they use complex instruments borrowing from the outside in addition to the basic instruments, their fatigue becomes the greatest, 3.09(F=7.831, P=.000). 11) As to the kind of operation, when they participate in orthopedic's surgery operations, they feel the greatest fatigue, 3.18(F=4.362, P=.000). With the above results, it is proved that the degree of operating room nurses' fatigue is considerably high. So it may be concluded that the measure for lessening the fatigue should be find immediately, not on the level of personal matters but on the level of hospital nursing administration.

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