• Journal of the Korean Graphic Arts Communication Society
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• v.8 no.1
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• pp.71-87
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• 1990

This paper presents a simple algorithm to obtain three dimensional information of an object. In the preprocessing of the stereo matching,feature point informations of stero image must be less sensitive to noise and well liked the correspondance problem. This paper described a simple technique of struture feature extraction of 3-D object and used edge-end point expanding method for unconnected line instade of Hough transform. The feature such as corner point and their angles are used for matching problem. The experimental results show that the described algorithm is a useful method for stereo correspondence problem.

• Transactions of Materials Processing
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• v.12 no.3
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• pp.236-243
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• 2003

Maintaining the required dimensional accuracy after springback becomes the main concern of sheet-forming die designers when formability is secured through beforehand tryouts. As a part to build guidelines for springback control in automobile frame forming, experiments are carried out to show the effects of process parameters, such as holding force, blank size, and lubrication, on corner angles of channels formed by U-bending or by square-cup drawing and trimming. The results predicted by a commercial FE package were compared with the experiment and the current limitations on springback evaluation were closely discussed.

• Proceedings of the Korean Geotechical Society Conference
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• 1996.10a
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• pp.97-106
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• 1996

• Journal of Energy Engineering
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• v.4 no.2
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• pp.297-302
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• 1995

Ignition of a reactive solid in a shape of square corner by a hot surface is studied theoretically. Ignition time and the location of ignition point are determined as a function of dimensionless parameters, with the use of the homogeneous model of ignition. The effect of geometry on the ignition of solid fuel results in the local characteristics: the reaction is initiated in a hot point in depth of the substance. It is shown that ignition time is proportional to the dimensionless initial temperature, whereas for the ignition of the semiinfinite body this dependence was quadratic.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.90-93
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• 2002

Assuring required dimensional tolerance after spingback becomes the main concern of sheet-forming die designers when formability is secured through previous tryout. As a part to build a guideline to control springback in automobile frame forming, experiments are carried out to show the effects of process parameters, such as holding force, blank size, and lubrication, on corner angles of channels formed by U-bending or by square-cup drawing and trimming. The results are resented in the viewpoint of evaluating parameters.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2337-2340
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• 2002

This paper presents the method of AGV(Automatic guided vehicle)'s moving environment(plane, corner, edge) recognition using SONAR sensor configuration. As for the SONAR sensor, the Crosstalk effect has been generally considered as an inevitable noisy phenomenon in the indoor environment. However, this effect can be used as a clue for classifying and localizing targets in the indoor environment if those can be controlled and used well. EERUF(error eliminate rapid ultrasonic firing) is a method for firing multiple ultrasonic sensors in mobile robot application and multi-echo mode of POLARIOD Device can reduce the Crosstalk effect. Here, Crosstalk effect was reduced using EERUF and applied to the AGV with a simple wall-following algorithm in the indoor environment. This method was tesed by a typical AGV with multi SONAR sensors in the laboratory environment.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.4
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• pp.141-148
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• 2000

Recently the Carbon Fiber Sheet(CFS) is widely used for strengthening damaged RC structures. Strengthening compression members such as column can increase ductility and strength due to the confinement effect. In this experiment, the behavior of concrete cylinders confined by CFS was examined. The confinement pressure is increased linearly as axial stress is increased in low axial stress, and the confinement effect of CFS was rapidly developed after near maximum axial stress, thus axial strength and ductility was improved. As the ratio of CPS is increased, concrete cylinders failed due to local fracture of CFS. The confinement effect of circular section is more efficient than that of rectangular section. And significant improvement of axial strength, axial strain, transverse strain at failure is observed in circular section. This is because in rectangular section the local fracture of CFS near corner may be occured, thus the strain efficiency ratio must be considered for RC structures with CFS.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.4
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• pp.521-530
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• 2014

In this paper, the glint effect of maritime target to a radar system was analyzed by simulation and field test with a barge and corner reflectors. From the experiment, we proposed a glint measurement method of a real maritime target and it was indicated that the glint effect between the simulation results and real measurement is similar. Also it was founded that the glint effect is related to the relative amount of RCS(Radar Cross Section) difference among major scattering point and minor scattering points. Finally, the experiment showed the glint effects of the rotating barge with some different combinations of scattering points.

• 한국전산유체공학회:학술대회논문집
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• 2004.03a
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• pp.196-201
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• 2004

Aerodynamic characteristics of three-dimensional wings in ground effect for Aero-levitation Electric Vehicle(AEV) are numerically investigated for various ground clearances and wing spans at the Reynolds number of $2\times10^6$. Numerical results show that a sizeable three-dimensional flow separation occurs with formation of an arch vortex at the junction of main and vertical wings, and that this is conjectured a primary cause for the high lift-to-drag(L/D) reduction rate of the main wing, when the wing span is decreased. Improvements on L/D ratios of the wings with small spans are pursued by breaking the coherence of superimposed adverse pressure gradients at the wing junction.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.6
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• pp.574-581
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• 2020

This paper describes the stacking effect for Ceramic Column Grid Array(CCGA) packages used for satellites. Reflow Soldering Process suitable for CCGA package with back structure was set as the process development goal to meet European Cooperation for Space Standardization(ECSS) standard. After analyzing the stacking effect according to the type of CCGA, it is verified by applying it to the CCGA Reflow Soldering Process. In order to confirm the validity of the staking effect analyzed in terms of vibration and thermal characteristics, it is verified through actual specimen production. It analyzes the cause of crack occurrence in the CCGA package and estimates the crack generation point using previously acquired inspection data.