• The Journal of Korean Medicine
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• v.20 no.2
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• pp.157-164
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• 1999

This study focused on the method of interpreting Moire's topography. There has been no standard of interpretation which informed, this study, The conclusions arc as follows: Miore's image closed contour lines which is consisted of points. These points in one contour have the same distances from the screen to the patient's back. Moire's index means the number of contour gaps from symmetrical point of a specific point with the axis of central line. The number of contours which pass the median line means the degree of antero-posterior curvature.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.3
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• pp.201-207
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• 2015

In this paper, in order to avoid equipment malfunction due to electromagnetic waves, which can occur when high-voltage live line diagnostic device fabrication, the enclosure structure of the diagnostic device with power lines that can minimize the EMI (electromagnetic interference) was modeled using the FEM (finite element method). Simulation examined the strength of the electric field in the required thickness, material and regions where there is a control board while changing the curvature radius of the corner making the enclosure, and By applying a mechanical design and simulation results that occur during the actual production has been designed for the final design. Most of the simulation results for the electric field is concentrated in the final model, the inner edge of the enclosure could be confirmed that the stable structure.

• Journal of the Korean Society for Railway
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• v.8 no.6 s.31
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• pp.550-558
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• 2005

The track performance evaluation in curves of conventional line subjected to loading condition caused by tilting trains was carried out. And the correlations between train speed and track alignment was reviewed. The parameters of track alignment were determined by field investigation of all curves in conventional line. It was founded that the pressure of the rail did exceed the allowable stress when the tilting train speed was over 96km/hr in radius of 300m. As the radius of curvature is smaller, applied force on the track becomes larger in the curved track without regard to laying of the continuos welded rail. On the while, the change of applied force on the track corresponding to the change of the cant is not so large.

• Journal of Sensor Science and Technology
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• v.14 no.5
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• pp.357-361
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• 2005

Low-stress silicon nitride (LSN) thin films with embedded metal line have been developed as free standing structures to keep microspheres in proper locations and localized heat source for application to a chip-based sensor array for the simultaneous and near-real-time detection of multiple analytes in solution. The LSN film has been utilized as a structural material as well as a hard mask layer for wet anisotropic etching of silicon. The LSN was deposited by LPCVD (Low Pressure Chemical Vapor Deposition) process by varing the ratio of source gas flows. The residual stress of the LSN film was measured by laser curvature method. The residual stress of the LSN film is 6 times lower than that of the stoichiometric silicon nitride film. The test results showed that not only the LSN film but also the stack of LSN layers with embedded metal line could stand without notable deflection.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1227-1234
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• 2011

Korea is a mountainous country, with as much as 70% of the area is covered by hills and mountains. This geography places constraints on the minimum radius of curvature for the rail network. It was expected that the speed of trains could be enhanced on the existing railway network without a huge investment in infrastructure by using tilting trains. The development of tilting trains in Korea started in 2001 as research & development project. A 6-car prototype test tilting train, called the Tilting Train eXpress (TTX), was built in December 2006 and experimental trials began in 2007. TTX has distributed power, is designed to run at 200 km/h, and has a planned service speed of 180 km/h. In this paper, we first describe the performance of tilting train, and then present the estimated running times, and the time saving compared with today's conventional trains and non-tilting trains, based on the Jungang line. So the time saving could be separated into two effects by higher track top-speed and tilting devices.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.405-410
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• 2001

In this paper, a new parametric curve interpolator is proposed based on a 3D(3-dimensional) NURBS curve. A free curve is generally divided into small linear segments or circular arcs in CNC machining. The method has caused to a command error, the limitation of machining speed, and the irregular machining surface. The proposed real-time 3D NURBS interpolator continuously generates a linear segment within the range of allowable acceleration/deceleration in the motion controller. Therefore, the algorithm calculates the curvature and the remained distance of a command curve for the smoothing machining. It is expected to attaining high speed and high precision machining in CNC Machine Tool.

• Tribology and Lubricants
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• v.28 no.5
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• pp.240-245
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• 2012

In this study, we developed a new carrier finger to prevent scratches in a sheet metal forming line. The developed carrier finger was designed to have a streamlined shape with a larger radius of curvature at the edges, as well as a smaller contact area. To evaluate the scratch alleviation effect, a sliding contact analysis and scratch test using the pin on a plate wear tester were conducted for both the old and new carrier fingers. The results show that, for both transverse and longitudinal movements of the strip, the newly designed carrier finger reduces both the friction and scratch depth by its streamlined shape, which decreases the pressure spike at the edge.

• Journal of Power System Engineering
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• v.5 no.3
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• pp.38-47
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• 2001

One stage axial type turbine is designed by mean-line analysis, streamline curvature method and blade design method using shape parameters. Tip and hub diameter of the turbine are 300mm and 206.4mm, respectively. The rotating speed is 1800RPM, and the output power is 1.4kW. The flow coefficient is 1.68 and the reaction factor at mean-line is 0.373. The number of stator and rotor of the turbine are 31 and 41, respectively. Mach number of stator exit flow near hub is 0.164. A test rig is developed for performance test to validate a developed design method. The experimental result shows that the maximum efficiency is obtained on the design point.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.11
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• pp.140-149
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• 1996

Cursive characters are written on an economical principle to reduce the motion of a pen in the limit of distinction between characters. That is, the pen is not lifted up to move for writing a next stroke, the pen is not moved at all, or connected two strokes chance their shapes to a similar and simple shape which is easy to be written. For these reasons, strokes and korean alphabets are not only easy to be changed, but also difficult to be splitted. In this paper, we propose a curvature stroke modeling method for splitting and matching by using a structural primitive. A curvature stroke is defined as a substroke which does not change its curvanture. Input strokes handwritten in a cursive style are splitted into a sequence of curvature strokes by segmenting the points which change the direction of rotation, which occur a sudden change of direction, and which occur an excessive rotation Each reference of korean alphabets is handwritten in a printed style and is saved as a sequence of curvature strikes which is generated by splitting process. And merging process is used to generate various sequences of curvature strikes for matching. Here, it is also considered that imaginary strokes can be written or omitted. By using a curvature stroke as a unit of recognition, redundant splitting points in input characters are effectively reduced and exact matching is possible by generating a reference curvature stroke, which consists of the parts of adjacent two korean alphasbets, even when the connecting points between korean alphabets are not splitted. The results showed 83.6% as recognition rate of the first candidate and 0.99sec./character (CPU clock:66MHz) as processing time.

• Journal of the Korean earth science society
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• v.40 no.4
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• pp.353-381
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• 2019

The general world model for homogeneous and isotropic universe has been proposed. For this purpose, we introduce a global and fiducial system of reference (world reference frame) constructed on a (4+1)-dimensional space-time, and assume that the universe is spatially a 3-dimensional hypersurface embedded in the 4-dimensional space. The simultaneity for the entire universe has been specified by the global time coordinate. We define the line element as the separation between two neighboring events on the expanding universe that are distinct in space and time, as viewed in the world reference frame. The information that determines the kinematics of the geometry of the universe such as size and expansion rate has been included in the new metric. The Einstein's field equations with the new metric imply that closed, flat, and open universes are filled with positive, zero, and negative energy, respectively. The curvature of the universe is determined by the sign of mean energy density. We have demonstrated that the flat universe is empty and stationary, equivalent to the Minkowski space-time, and that the universe with positive energy density is always spatially closed and finite. In the closed universe, the proper time of a comoving observer does not elapse uniformly as judged in the world reference frame, in which both cosmic expansion and time-varying light speeds cannot exceed the limiting speed of the special relativity. We have also reconstructed cosmic evolution histories of the closed world models that are consistent with recent astronomical observations, and derived useful formulas such as energy-momentum relation of particles, redshift, total energy in the universe, cosmic distance and time scales, and so forth. The notable feature of the spatially closed universe is that the universe started from a non-singular point in the sense that physical quantities have finite values at the initial time as judged in the world reference frame. It has also been shown that the inflation with positive acceleration at the earliest epoch is improbable.