• Proceedings of the Korean Nuclear Society Conference
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• 1997.05a
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• pp.392-399
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• 1997

An approximation technique was developed for the simulation of free surface flows in non-orthogonal coordinates. The main idea of this approach is to approximate VOF by the second order linear equation in the transformed domain on the assumption that the continuity of free surface would be maintained. The method was justified through a set of numerical test to examine if its original shape could be maintained when the circles are convected in uniform velocity in horizontal direction in curvilinear coordinates. Finally a simple problem was solved by applying the method to CFX4.1 general purpose CFDS code.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.28 no.3
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• pp.252-261
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• 1992

The accuracy of the position fixing with telemetry techniques depends in general on the accuracy of the location of the receiving point(hydrophone). To increase the accuracy of the coordinates of four hydrophones suspended down at both sides of the vessel anchored, each hydrophone motion is compensated using a depth pinger mounted on the seabed of 30m depth. The pinger location is calculated with a hyperbolic method. Using this technique so called hydrophone coordinates calibration, the movement of the Remotely Operated Vehicle(ROV), which has the same type of pinger mentioned above could be tracked down more accurately. Under the maximum variation ranges of a hydrophone of 5.2m in athwartships, 3.2m in alongship, and about 0.2m/s of the moving velocity in both directions, the ROV track with calibration is more close to the reality than that without calibration Tow depth pingers of same frequency can be distinguished by the use of three factors; The pulse period, the phase and the pulse period variation allowed in acquisition of the pinger as far as its pulse period is varied in smooth.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.15 no.2
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• pp.253-261
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• 1997

In general, the transformation of coordinates in GPS is carried out by 3 dimensional transformation method with 3-10 parameter. In korea, the coordinates of transformation points ware determined are adjusted in-dependently by planimetry and the height, and also the weight of observations were not properly applied to the adjustment. In this study, two different transformation methods are tested and analysed by the field test, and it is finally found that 2 dimensional method is more efficient way than 3 dimensional classical transformation method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.999-1002
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• 2002

Cylindrical Cam Mechanism is widely used in the fields of industries, such as machine tool exchangers, textile machinery. This paper proposes a method for manufacturing of cylindrical cam in Multi CNC machining center. Multi CNC machining center has two different types depending on the tilting axis. For the manufacturing procedures. in this paper the location and the orientation of cutter path are defined from shape design data of cam. The integral NC code fur the both types of multi-axis CNC machining center can be created using the coordinates mapping between design coordinates and work coordinates. Finally, CAD/CAM program is developed on $C^{＋＋}$ language. This program can display manufacturing and kinematics simulation, which can make integral NC code for multi-axis CNC machining center of two types.

• Korean Journal of Optics and Photonics
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• v.17 no.6
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• pp.525-531
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• 2006

Synthesized 3-D CGH of a general three dimensional object is obtained by using a new 3-D coordinates transformation technique. A CCD camera is used to record several projected images of the 3-D object from different viewing angles. The recorded data are numerically calculated and processed to yield two-dimensional complex functions, which are then encoded fer the final synthesized 3-D CGH.

• 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.

• Journal of Mechanical Science and Technology
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• v.17 no.1
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• pp.129-138
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• 2003

A 1 : 20 laboratory scale test rig of a 200 MW tangentially fired boiler is built up with completely simulated structures such as platen heaters and burners. Iso-thermal turbulent flow in the boiler is mapped by 3-D PDA (Particle Dynamic Analyzer). The 3-D numerical models for the same case are proposed based on the solution of к-$\varepsilon$ model closed RANS (Reynolds time-Averaged Navier-Stokes) equations, which are written in the framework of general coordinates and discretized in the corresponding body-fitted meshes. Not only are the grid lines arranged to fit the inner/outer boundaries. but also to align with the streamlines to the best possibility in order to reduce the NDE (numerical diffusion errors). Extensive comparisons of profiles of mean velocities are carried out between experiment and calculation. Predicted velocities in burner region were quantitatively similar with measured ones, while those in other area have same tendency with experimental counterpart.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.8 s.239
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• pp.1123-1131
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• 2005

In this paper, a formulation for a spatial sliding joint, which a general multibody can move along a very flexible cable, is derived using absolute nodal coordinates and non-generalized coordinate. The large deformable motion of a spatial cable is presented using absolute nodal coordinate formulation, which is based on the finite element procedures and the general continuum mechanics theory to represent the elastic forces. And the non-generalized coordinate, which is neither related to the inertia forces nor external forces, is used to describe an arbitrary position along the centerline of a very flexible cable. In the constraint equation for the sliding joint, since three constraint equations are imposed and one non-generalized coordinate is introduced, one constraint equation is systematically eliminated. Therefore, there are two independent Lagrange multipliers in the final system equations of motion associated with the sliding joint. The development of this sliding joint is important to analyze many mechanical systems such as pulley systems and pantograph/catenary systems for high speed-trains.

• The Journal of Korean Physical Therapy
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• v.22 no.2
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• pp.39-46
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• 2010

Purpose: This study was designed to determine whether General Coordinative Manipulation (GCM) Intervention Models have effects on the balanced restoration of asymmetrical muscles in the extremities. Methods: Fifty-nine healthy subjects (1st hypothesis: n=40, 2nd hypothesis: n=19) participated in studies using the two GCM intervention models. Subjects were studied 2 times a week for 3 weeks. Electromyography (EMG) was used to measure muscle activity, and measurements were performed before and after the application of the each intervention model. Results: Hypothesis 1: GCM Intervention, which coordinates flexion types of muscle contractions of the upper extremity and extension types of muscle contractions of the lower extremity (excluding self-care) is effective for treating shows the treatment in efficiency on more than two 2 of 3 muscles (vastus medialis, gastrocnemius medial, and deltoid middle) and the effects affects on more than 3 types of 4 body types (Vastus medialis, Gastrocnemius medial of Body type III, p<0.05). GCM body type was classified by the relative tilting of right and left scapulars and iliums into four groups. Hypothesis 2: GCM Intervention, which coordinates flexion types of muscle contractions of the lower extremity and extension types of muscle contractions of the upper extremity (excluding self-care) is effective for treating more than two 2 of 3 muscles (vastus medialis, gastrocnemius medial, and deltoid middle) and the effects affects on more than 2 types of 3 body types (p>0.05).

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.82.1-82.1
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• 2011

We present a new code for solving non-LTE radiative transfer problems in a general grid (RIG). RIG develops from RATRAN code (Hogerheijde & van der Tak 2000) using the Accelerated Monte-Carlo method, and it can cope with line overlap effect among multiple molecular and atomic species. In this algorithm we make grids in arbitrary coordinates adequate to the problem, but, on the other hand, photons propagate in the Cartesian coordinates. For spherical, cylindrical and other well defined coordinate, the problem of tracing photon's path reduces to solving simple quadratic equations. For example, the outflow in the star formation have high dynamic range in scales from a few AU to ~ 0.1 pc and have also cylindrical symmetry. So, we have used (r, ${\alpha}$) coordinate system, where r is the distance from the origin and ${\alpha}$ is z/ R2 in the cylindrical coordinate of (R,z). The (r, ${\alpha}$) coordinate realizes the density - power function of r - and temperature distributions of the problems with smaller numbers of grid than the cylindrical coordinate does, and the former consumes less time to solve the problems than the latter.