• Title/Summary/Keyword: Fundamental Coordinates

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Adjustment Computation of the National Fundamental Stations Using 3-D Baseline Vectors(KTRF94) (3차원 기선벡터망 조정기법에 의한 국가기본점의 성과산정(KTRF94))

  • 이영진
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.16 no.1
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    • pp.85-94
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    • 1998
  • In year 1996, the National Geography Institute(NGI) carried out a National Fundamental Network survey. A total of 220 baselines between 31 stations were occupied that the baseline length is 40 km-120 km(mean 67.4 km). A minimally constrained network adjustment with three dimensional baseline vectors, was carried out holding geocentric ITRF94 coordinates of the station SUWON which are determined by eccentric observations from the VLBI station. This paper shows KTRF94 coordinates of fundamental stations which accuracies are estimated 1 cm in horizontal and 3 cm in vertical. Also, the coordinates are compared to WGS84 and/or KGS95.

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On 'Logical Space' of the Tractatus (『논리-철학 논고』의 '논리적 공간'에 관하여)

  • Park, Jeong-il
    • Korean Journal of Logic
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    • v.19 no.1
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    • pp.1-49
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    • 2016
  • In the Tractatus, 'logical space' raises the several puzzles as follows. What are logical space, logical coordinates and logical place? What is the point of such analogies and what do they refer to exactly in the Tractatus? And what do occupy logical space? Can facts, proposition, propositional sign, situation and contradiction occupy it respectively? Or is it impossible to reconcile the remarks concerning logical place in the Tractatus? Futhermore, why did Wittgenstein need the concept of logical space? What is the problem that he tried to solve through this concept? In this paper, I will endeavor to answer to these problems. Logical space in the Tractatus is the system of propositions with senses. And it is the concept which Wittgenstein contrived by making model of Hertz's configuration space. Wittgenstein's fundamental coordinates are in some ways similar to geometrical ones. On the other hand logical coordinates are completely different from geometrical ones. Hence attempts to understand logical space by a kind of geometrical spaces cannot be right at all.

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An Isometric Shape Interpolation Method on Mesh Models (메쉬 모델에 대한 아이소메트릭 형상 보간 방법)

  • Baek, Seung-Yeob;Lee, Kunwoo
    • Korean Journal of Computational Design and Engineering
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    • v.19 no.2
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    • pp.119-128
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    • 2014
  • Computing the natural-looking interpolation of different shapes is a fundamental problem of computer graphics. It is proved by some researchers that such an interpolation can be achieved by pursuing the isometry. In this paper, a novel coordinate system that is invariant under isometries is defined. The coordinate system can easily be converted from the global vertex coordinates. Furthermore, the global coordinates can be efficiently recovered from the new coordinates by simply solving two sparse least-squares problems. Since the proposed coordinate system is invariant under isometries, then transformations such as global rigid trans-formations, articulated posture deformations, or any other isometric deformations, do not change the coordinate values. Therefore, shape interpolation can be done in this framework without being affected by the distortions caused by the isometry.

A Study of Nonlinear Color Conversion by Neural Networks (신경망을 이용한 비선형 색 변환에 관한 연구)

  • 김석철
    • Journal of the Korean Graphic Arts Communication Society
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    • v.14 no.2
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    • pp.115-128
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    • 1996
  • In this paper, we describe the Color Correction and Preferred Skin Color Reproduction in a ink-jet color printer. The fundamental color correction that converts RGB densities into GMY densities has been ordinarily used. This method can reduce the hue error, but color difference between the preferred skin colors and hardcopy skin colors are large. We have been able to reduce color differences between original skin color and hardcopy skin color by transforming hardcopy skin colors` coordinates into Preferred Skin Colors` coordinates. Experimental results show that the described method is useful and valid for the skin color reproduction in a digital color printer.

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Development of Zonal-Embedded-Grid Method for a Polar Coordinate System and Application to the Spin-up Flow within a Semi-Circular Cylinder

  • SUH Yong Kweon;YEO Chang-Ho
    • 한국가시화정보학회:학술대회논문집
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    • 2004.12a
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    • pp.81-90
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    • 2004
  • A zonal embedded grid technique has been developed for computation of the two-dimensional Navier-Stokes equations with cylindrical coordinates. The fundamental idea of the zonal embedded grid technique is that the number of azimuthal grids can be made small near the origin of the coordinates so that the grid size is more uniformly distributed over the domain than with the conventional regular-grid system. The code developed using this technique combined with the explicit, finite-volume method was then applied to calculation of the spin-up flows within a semi-circular cylinder. It was shown that the numerical results were in good agreement with the experimental results both qualitatively and quantitatively.

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Compensating Performance Evaluation of Active Power Filters Using the Expanded 3-D Current Coordinates (확장된 3차원 전류 좌표계에 의한 능동전력필터의 보상성능 평가)

  • Kim, J.G.;Lim, Y.C.;Jung, Y.G.
    • Proceedings of the KIEE Conference
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    • 2003.04a
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    • pp.292-295
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    • 2003
  • Conventional methods in time / frequency domain for evaluating the compensation performance of active power filters are not provided easy solutions. So, the authors have previously proposed 3-D current coordinates which is composed into active component, fundamental reactive component and distorted component of nonlinear loads current. This method has excellent performance, but can not evaluate the characteristics of nonlinear load current whether it is inductive or capacitive. Therefore, To overcome problems mentioned previously, this paper deals with the simple Average power theory and the expanded 3-D current coordinates for evaluating the compensation performance of active power filters. To confirm the validity, active power filters simulator is developed using C-language. From the simulation, results are discuss their utility.

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Digital Image Analysis(DIA) of Color Changes in Field Growing Stages for Rice (벼의 성장단계별 색 변화에 관한 디지털 화상해석)

  • Park, Jong-Hwa;Shin, Yong-Hee;Park, Min-Seo
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2003.10a
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    • pp.623-626
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    • 2003
  • Image analysis was performed with two color systems, Red-Green-Blue (RGB) values and normalized Hue-Saturation-Intensity (HSI). We conducted field studies in Cheongju to determine canopy spectral reflectance and digital image analysis of rice. Spectral reflectance measurements made with a portable spectrometer(LI-1800) correlated with growing stage and digital images for rice. Images in which the color was specified by the common RGB coordinates could be used when there was a sharp contrast between the color of the rice and that of the field soil. In the absence of sharp contrast, identification of the rice covered area was much easer after the color had been transformed into HSI coordinates. This study introduced fundamental theories in digital image analysis and applied that for field situations rice.

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Development of a New Robot Manipulator Driven by the Closed-chain Actuator (폐체인 구조의 새로운 다관절 로봇 매니퓰레이터 개발)

  • 최형식;백창열
    • Journal of Advanced Marine Engineering and Technology
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    • v.27 no.2
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    • pp.238-245
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    • 2003
  • To overcome the weakness in the load capacity of conventional robot manipulators actuated by motors with the speed reducer such as the harmonic driver, we proposed a new closed-chain type of the robot actuator which is composed of the four-bar-link mechanism driven by the ball screw. The robot manipulator is revolute-jointed and composed of four axes. The base axis is actuated by the lineal actuator such as the ball screw, and the others are actuated by the proposed actuator. We analyzed the mechanism of the actuators of the robot joints, and developed the dynamics model. The dynamics are expressed in the joint coordinates and then they are mapped into the sliding coordinates of the ball screw. We performed fundamental tests on the structure of the robot.

A Study on Online Detection Schemes of Earthquake Induced Shifts in Coordinate Time Series of GNSS Continuous Operation Reference Station by Kalman Filtering (칼만필터에 기반한 GNSS 상시관측소 좌표 시계열의 지진에 따른 편의검출 기법에 관한 연구)

  • Lee, Hungkyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.9
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    • pp.662-671
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    • 2020
  • It is crucial to manage and maintain the geodetic reference coordinates of GNSS continuously operating reference stations (CORSs) in consideration of their fundamental roles in geodetic control and positioning navigation infrastructure. Earthquake-induced crustal displacement directly impacts the reference coordinates, so such events should be promptly detected, and appropriate action should be made to maintain the target accuracy, including update of the geodetic coordinates. To this end, this paper deals with online schemes for the detection of persistent shifts in the coordinate time-series produced by an automatic GNSS processing system. Algorithms were implemented to test filtered results, such as hypothesis tests of the innovation sequence of a Kalman filter and a cumulative sum (CUSUM) test. The results were assessed by the time-series of coordinates of 14 CORS for two years, including the 2011 Tohoku earthquake. The results show that the global hypothesis test is practical for detecting abrupt jumps, whereas CUSUM is effective for identifying persistent shifts.

Actual Condition of Inconsistency at the Boundary Areas of Administrative Districts (행정구역 경계지역에서의 지적불부합지 실태분석)

  • Hong, Sung-Eon
    • Journal of Korean Society for Geospatial Information Science
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    • v.16 no.1
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    • pp.57-65
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    • 2008
  • This research is aimed at offering a fundamental data for the adjustment of cadastral inconsistency of administrative boundary areas from this time onward by analyzing actual conditions of cadastral inconsistency at the study areas by the use of digital topographic map and digital cadastral map of si-gun-gu boundary area. As a result of examining the actual condition of cadastral inconsistency at the surveyed areas, the extent of cadastral inconsistency of the neighboring administrative boundary areas was assessed as ${\pm}3.15m$ of RMSE on X coordinates and also assessed as ${\pm}2.85\;m$ of RMSE on Y coordinates; in addition, RMSE of the neighboring district of the administrative boundary areas on X coordinates was assessed as ${\pm}1.33\;m$, and ${\pm}0.75\;m$ of RMSE on Y coordinates respectively-thus, this research could suggest the fact that there has arisen a lot of cadastral inconsistency areas at administrative boundary areas.

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