• Journal of Industrial Technology
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• v.18
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• pp.363-370
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• 1998

This study focused on the development of an alternative stress estimation procedure to instantly calculate the critical stresses bonded concrete pavement. Closed form analysis is commonly used to analyze pavement structures. This type of analysis assumes linearelastic material properties and static loading conditions. The well-known ILLI-SLAB finite element program was used for the analysis. Bonded concrete overlay analyzed the stress distribution, behavior and load carrying capacity under track load is made evaluation standard of bonded concrete overlay. In the study, the following results were derived ; The properties of strength is that compress and 3-point bending strength of existing pavement is deteriorated with $184kg/cm^2$, $59kg/cm^2$ but compress and splitting tensile strength of overlay is satisfied with $465kg/cm^2$, $45kg/cm^2$. Load transfers is happen at adjacent slab by interlocking under track load. The stress distribution under interior, corner and edge load is described high loading position surrounding then loading position.

• Ocean Systems Engineering
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• v.12 no.4
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• pp.461-477
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• 2022

Dynamic Positioning (DP) is a system that uses computer-controlled thrusters, propellers, and other propulsion devices to automatically maintain a vessel's position and heading. In this study, a wind turbine installation vessel with DP capabilities was proposed for use in mild environmental conditions in the Yellow Sea. The thruster arrangements of the vessel were analyzed in relation to wind and current loads, and it was found that a four-corner arrangement of thrusters provided the best position-keeping performance. The vessel's DP control performance was also analyzed in relation to the increased environmental load caused by the presence of a wind turbine, using a capability plot. The vessel's performance was evaluated in three different states: floating with no load, during the loading of a wind turbine and suction buckets, and after the wind turbine has been installed. The use of 750 kW and 1,000 kW thrusters was also considered, and the environmental loads in the Saemangeum coastal area and the environmental load when a 5-Megawatt wind turbine is on board were assessed. The study concluded that at least four thrusters should be used for DP to safely manage the installation process of wind turbines.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2002.11a
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• pp.321-326
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• 2002

To design mechanical ventilation for bathroom of apartment houses where air supply and exhaust are taken Into consideration, mock-ups of ventilation systems, widely used in bathroom of apartment houses with an area of 100$m^2$, were made and installed in a laboratory, These ventilation mock-ups were available for control of air supply and exhaust, and the size of supply openings were 40cm$\times$1cm, 40cm$\times$3cm, 40cm$\times$5cm. They were installed at five positions, spaced 40cm at a height of 25cm from the floor. and the position of exhaust fans were four corners and center Exhaust fan established each one on corner of the ceiling and one in center. As result that measure ventilation effect by each condition, size of hole that supply air is big, and ventilation effect took effect to be good establishment location is low, Also, distance of exhaust fan is far with hole that supply air, ventilation effect took effect by superior thing.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1227-1230
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• 2003

In this paper, we propose a pose estimation method using local map acquired from 2d laser range finder information. The proposed method uses extended kalman filter. The state equation is a navigation system equation of Nomad Super Scout II. The measurement equation is a map-based measurement equation using a SICK PLS 101-112 sensor. We describe a map consisting of geometric features such as plane, edge and corner. For pose estimation we scan external environments by laser rage finer. And then these data are fed to kalman filter to estimate robot pose and position. The proposed method enables very fast simultaneous map building and pose estimation.

• Korean Journal of Materials Research
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• v.16 no.1
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• pp.25-29
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• 2006

Vertical growth of iridium-catalyzed carbon nanofibers could be selectively grown on the MgO substrate using microwave plasma-enhanced chemical vapor deposition method. Growth positions of the iridium-catalyzed carbon nanofibers on the MgO substrate could be manipulated according to the applied bias voltage. At-150 V, the carbon nanofibers growth was confined only at the corner area of the substrate. Based on these results, we discussed the cause for the confinement of the vertically grown carbon nanofibers on the specific area of the MgO substrate as a function of the applied bias voltage.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.61-62
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• 2006

The suppression of fluid force acting on a square prism near plane wall was studied by attaching fences on the comers of the prism. The height of the fence was 10% of the square width and the range of Reynolds number considered was $Re=2.0{\times}10^4$. The experimental parameters were the attaching position and numbers of fences, the space ratios $G/B(G/B=0.1{\sim}1.2)$ between prism and plane wall. The average drag coefficients were increased and the average hit coefficients were decreased and increased with the space ratios foulard plane wall. The drag of the prism was reduced average 7.6% with the space ratios by attaching the normal fence at the rear and upper comer and the horizontal normal fence at the rear and lower corner on the prism.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.505-507
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• 2004

This paper presents a measurement of ZMP using FSR sensors, and then the ZMP control with measured ZMP on single leg. ZMP is mostly used as standard evaluation of stability of a humanoid robot. The ISHURO has 5 sensors which are mounted at each corner and center of a sole. ZMP is computed using a model of a humanoid robot and information from the joint encoders. And we may able to use measurement data from FSR sensors at the robot feet. IP(Integration Proportional) control algorithm is applied to position control of ZMP that is an error of desired ZMP between measured ZMP.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.6
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• pp.111-116
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• 2018

Recently, shape manufacturing method has been changed to a 3D printer. Since lamination type manufacturing method is the basis for forming a three-dimensional shape by repeated lamination, the horizontal accuracy of the lamination layer is very important. In the current paper, we have proposed a new leveling system to be installed in a large 3D printer. The light source was reflected from the water surface contained in the measuring device, and the inclination of the measuring device was measured from the light that entered into four regions of a quarter photodetector. The electrical signals generated differently according to the position of the beam spot incident on the quarter photodetector was acquired and compensated to be horizontal by using a motor mounted at the corner. Compared to a digital leveler, the newly developed leveling system gave errors of only 2 to 3%. This new device can be applied to various fields including the 3D printer in future.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1997.04a
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• pp.210-217
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• 1997

This paper presents the numerical results of the stress analysis of wheel-rail contact problems. Two models which have straight and tapered(1:20) contact geometries between the wheelset and rail are analyzed using the finite element approach. From the simulation results we found that the tapered geometry of wheel-rail contact base line showed very stable contact stress distributions for a whole contact position between the wheel and rail in a curved rail section. The FEM computed results may present an optimized geometry of wheel-rail contact in a high-speed railway system.

• Transactions of Materials Processing
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• v.7 no.4
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• pp.382-392
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• 1998

Computer simulations and test trials were carried out to obtain the optimal stamping conditions of the die design of the laser welded automotive body. The stamping process including gravity deflection bead calibration binder wrap, forming and spring back was simulated and compared with the results obtained from test trials. The production variables were determined from a preliminary operation and they were investigated in the simulation and the test trials. The formability was tested under the various conditions, such as the initial position of blank, blank holding force, corner radius and the shape of drawbead. Sound products without fracture, wrinkling and excessive weldline movement were produced by applying results obtained this investigation.