• Journal of architectural history
• /
• v.10 no.2 s.26
• /
• pp.21-34
• /
• 2001

The purpose of this study is that it is made clear the construction method of Japanese Castle Architecture in Korea as I study the construction method of Suncheon-Japanese Castle(順天倭城) in those days of Jeong-yu Japanese Invasion. Moreover, I intend to analyze the similarity and the difference between Suncheon-Japanese Castle and Korean Castle Architecture by a comparative study. The result of the study is showed that Suncheon-Japanese Castle seemed to be built with the object of a long time stay rather than it was of strategic importance for the national defense. In addition, it was different from other Japanese Castle in Korea because the watch tower(天守閣) of it stood in the middle of stronghold and the watch tower stronghold dividing the round of it while that of it stood the comer of stronghold. The face stone used in important part of watch tower, gate, and so on was mostly a trimed hexangular stone. On the other hand, the face abbuting on the Gulf of kwang-yang was made of naturally wild face stone. The stone cleared traces of Si-hyeol(矢穴) and domestic Castle in Japan was also made of this method after Im-Jin Japanese Invasion. According to the construction method, the wall of castle made use of the Netak(內托) method except the gate, the support stronghold and the watch. The early mountain castle in Korea have this construction method in common.

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.4
• /
• pp.127-133
• /
• 2008

As the application of the MEMS parts increases, the structural safety of MEMS appears importantly. A lot of MEMS parts are made by a multi-grain silicon wafer, which is an orthotropic material. Moreover directions of the materials on each grain are distributed randomly. The stress analysis for the multi-grain is important factor in order to apply the MEMS parts to industrial applications. The finite element method (FEM) is commonly used by a stress analysis method but the boundary element method (BEM) is known as the result of the BEM is more accurate than that of the FEM since the fundamental solution are used. In this study, we derived the boundary integration equation for the orthotropic material by applying fundamental solutions with complex variables. The multi-region analysis procedure for the BEM and the multi-grain generation procedure by a random process technique are developed in order to apply the analysis of the multi-grain orthotropic material. The discontinuous element is used in order to remove the comer problem in the BEM. The results of the present method are compared with those of the finite element method in order to verify the present procedure.

• Journal of KIISE:Computer Systems and Theory
• /
• v.36 no.3
• /
• pp.217-230
• /
• 2009

In this paper we propose a new CBL-based floorplan method that accommodates pre-placed blocks. We identify the problem of the previous CBL-based pre-placed block floorplan method, and suggest the solution method of this problem. In our method, CBLs consisting of only free blocks are perturbed and maintained during the simulated annealing. Pre-placed blocks are inserted during packing in such a way that the topology of the CBL after insertion of a pre-placed block resembles the topology before insertion. Thus, even with the inclusion of pre-placed blocks, the searching effort via simulated annealing yields acceptable results. Experimental results show that our floorplan method places pre-placed blocks effectively and efficiently.

• Proceedings of the KSRS Conference
• /
• 2007.10a
• /
• pp.254-257
• /
• 2007

This paper presents an examination of the spatial integration method for extracting the RCS of a trihedral corner reflector from SAR images for SAR external calibration. An exact external radiometric calibration technique is required for extracting an exact calibration constant. Therefore, we examine the accuracy of the spatial integration method, which is commonly used for the SAR external radiometric calibration. At first, an SAR image for a trihedral corner reflector is simulated with a high-resolution SAR impulse response with a known theoretical RCS of the reflector, and a background clutter image for the high resolution SAR system is also generated. Then, a SAR image in a high resolution is generated for a trihedral comer reflector located on a background clutter by superposition of the two SAR images. The radar cross section of a trihedral corner reflector in the SAR image is retrieved by integrating the radar signals of the pixels adjacent to the reflector for various size of the integration area. By comparison of the measured RCS by the integration method and the theoretical RCS of the reflector, the effect of the size of the integration area on the extraction of the calibration constant is examined.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.25 no.10
• /
• pp.1671-1677
• /
• 2001

Cracks at mechanical fastener holes usually nucleate as elliptical comer cracks at the faying surface of the mechanical joints and grow as elliptical arc through cracks. The weight function method for elliptical arc through cracks at mechanical fastener holes has been developed and verified in the part I of this study. In part H, applying the weight function method, the effects of the amount of clearance on the mixed-mode stress intensity (actors are investigated and the change of crack shape is predicted from the analysis for various crack shapes. The stress intensity factors leer inclined crack are analyzed and critical angle at which mode I stress intensity factor becomes maximum is determined.

• Proceedings of the KSME Conference
• /
• 2001.06b
• /
• pp.319-324
• /
• 2001

This paper presents the motion control of a mobile robot with arc sensor for lattice type welding. Its dynamic equation and motion control method for welding speed and seam tracking are described. The motion control is realized in the view of keeping constant welding speed and precise target line even though the robot is driven along a straight line or corner. The mobile robot is modeled based on Lagrange equation under nonholonomic constraints and the model is represented in state space form. The motion control of the mobile robot is separated into three driving motions of straight locomotion, turning locomotion and torch slider controls. For the torch slider control, the proportional integral derivative (PID) control method is used. For the straight locomotion, a concept of decoupling method between input and output is adopted and for the turning locomotion, the turning speed is controlled according to the angular velocity value at each point of the comer with range of $90^{\circ}$ constrained to the welding speed. The experiment has been done to verify the effectiveness of the proposed controllers. These results are shown to fit well by the simulation results.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.44 no.10
• /
• pp.17-22
• /
• 2007

This paper presents a baseband complex bandpass filter for PHS applications with a new automatic tuning method. The full-CMOS PHS transceiver is implemented by adopting the Low-IF architecture to overcome the DCoffset problems. To meet the Adjacent Channel Selectivity (ACS) performance, the 3rd-order Chebyshev complex bandpass filter is designed as the baseband channel-select filter. The new corner frequency tuning method is proposed to compensate the process variation. This method can reduce the noise level due to MOS switches. The filter was fabricated using a 0.35{\mu}m$ CMOS process, and the power consumption is 12mW.

• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.6
• /
• pp.143-152
• /
• 2000

The comer filling in shaped drawing process is an important characteristic, unlike the round drawing. It has also influence on the dimensional accuracy of the product. In this study, therefore, the shaped drawing process has been simulated by the three dimensional rigid-plastic finite element method in order to investigate the effect of process variables such as reduction in area and semi-die angle to the corner filling. The artificial neural network has also been introduced to reduce the number of simulations. To verify the results of simulations, experiments have been performed on the real industrial products. According to the results, the main process variable on the corner filling is the combination of semi-die angle in the irregular shaped drawing processes, but in the case of regular shaped drawing processes, reduction in area has great influence on the corner filling.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2004.11a
• /
• pp.259-265
• /
• 2004

No matter how well the equally spaced grounding grid is designed, there are questions keep rising, such as leakage of current from comer conductor, high voltage of touch voltage in corners of grid than in center, and high material cost for grounding grid. The best-fitted design for unequally spaced grounding grid is a part that must be considered. Explain advantages of unequally spaced grounding grid and lead formula by dividing the number of grid division, j, into 20, instead of 7. Then present $D_{ij}$, which is optimum rate for unequally spaced grounding grid and verify safety and economy of the unequally spaced grounding grid by computer simulation with a poly-nominal function form.

• 한국전산유체공학회:학술대회논문집
• /
• 2000.05a
• /
• pp.27-32
• /
• 2000

In this study, the three-dimensional blood flow within the sac of KTAH(Korean artificial heart) is simulated using fluid-structure interaction model. The numerical method employed in this study is the finite element commercial package ADINA. The thrombus formation is one of the most critical problems in KTAH. High fluid shear stress or stagnated flow are believed to be the main causes of these disastrous phenomenon. We solved the fluid-structure interaction between the 3D blood flow in the sac and the surrounding sac material. The sac material is assumed as linear elastic material and the blood as incompressible viscous fluid. Numerical solutions show that high shear stress region and stagnated flow are found near the upper part of the sac and near the comer of the outlet during diastole stage.