• Journal of Ocean Engineering and Technology
• /
• v.25 no.1
• /
• pp.8-13
• /
• 2011

A compact array system of small buoys is used for wave energy extraction. To evaluate the performance of this system, hydrodynamic analysis is carried out in regular waves using the higher order boundary element method. The motion response of each buoy is calculated considering hydrodynamic interactions caused by other buoys. The effect of energy extraction device is modeled as a linear damping load. The efficiencies of energy conversion are compared using the various sizes and arrangements of the array system and the damping coefficients for energy extraction. The increase in size or the packing ratio of the system gives better efficiency. However, the wave condition and the cost for the system should be considered to optimize performance from the perspective of engineering and economics. The proposed nondimensionalized damping coefficient for energy extraction is 0.1~0.5.

• Journal of the Korean Ceramic Society
• /
• v.30 no.10
• /
• pp.859-865
• /
• 1993

Morphotropic tetragonal and rhombohederal phase boundary(MPB) in PZT system was calculated and the effect of mechanical stress and electric field on the MPB was examined using phenomenological thermodynamic theory proposed by Devonshire. Mechanical stress and electric field was calculated to change free energies of phases and shift MPB. The stable composition range of the phase, of which spontaneous strain and spontaneous polarization aligned to the direction of tensile stress or electirc field, was expanded.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.72-72
• /
• 2000

This paper presents a methodology combining sliding mode control and fuzzy control to tune the boundary layer and input gain according to the system state. The equivalent control is designed such that the nominal system exhibits desirable dynamics, The robust control with fuzzy self-tuning is then developed to guarantee the reaching condition and reduce chattering phenomenon in the presence of parameter and disturbance uncertainties.

• Journal of Korea Society of Industrial Information Systems
• /
• v.3 no.1
• /
• pp.258-268
• /
• 1998

This paper presents two sequential advanced split and merge algorithms and a parallel image segmentation algorithm based on them. First, the two advanced methods are obtained from the combination of edge detection and classic split and merge to solve the inherent problems of the classical method. Besides, the parallel image segmentation algorithm on mesh-connected MIMD system considers three types in the merge stage to reduce the communication overhead between processors, such as intraprocessor merge, interprocessor with boundary merge, and interprocessor without boundary merge. Finally , we prove that the proposed algorithms achieve the improved performance by implementing them.

• Bulletin of the Korean Mathematical Society
• /
• v.27 no.2
• /
• pp.165-172
• /
• 1990

In this paper, we study a method which speeds up the convergence of monotone iterations and give some numerical examples of the types (2) and (3). In [2] this method has been applied to a system of hyperbolic differential equations with initial and boundary conditions.

• Magazine of the Korea Institute for Structural Maintenance and Inspection
• /
• v.18 no.3
• /
• pp.32-37
• /
• 2014

• East Asian mathematical journal
• /
• v.39 no.3
• /
• pp.305-317
• /
• 2023

We establish the existence and uniqueness of Green functions in Lipschitz domains for stationary Stokes systems with Neumann boundary conditions. For the uniqueness, we impose a different normalization condition from that in Choi et al. (J. Math. Fluid Mech., 20(4):1745-1769, 2018).

• The KIPS Transactions:PartA
• /
• v.16A no.2
• /
• pp.79-88
• /
• 2009

In boundary scan architecture, test stimuli are shifted in one at a time and applied to the on-chip system logic. The test results are captured into the BSR and are examined by subsequent shifting. In this paper, we developed a continuous capture test architecture and test procedure using TPG based on boundary scan is used to performance test. In this architecture, test patterns of TPG are applied to CUT with system clock rate, and response of CUT is continuously captured by CBSR(Continuous Capture Boundary Scan Register) at the same rate and the captured results is shifted to TDO at the same rate. The suggested a continuous capture test architecture and test procedure is simulated by Altera Max+Plus 10.0. The simulation results shows the accurate operation and effectiveness of the proposed test architecture and procedure.

• Proceedings of the Technology Innovation Conference
• /
• 1996.12a
• /
• pp.241-264
• /
• 1996

This article introduces the five functions of the national innovation system (NIS). As the national innovation system is a kind of social systems in the national level, the five generic functions of open system-production boundary spanning, maintenance, adaptation management functions-are applied to the NIS. The production function is the primary process, which produces innovative products and services of the NIS. The boundary spanning function is the function of procuring the input and disposing the innovation output or aiding in these process. Experienced R&D human resources, R&D funds, technology etc. belong to the input of the NIS. The maintenance function is responsible for the smooth operation and upkeep of the system in terms of various conditions. The adaptive function is to help the system change and adapt, scan the environment for problems, opportunities, and technological developments. It faces outward for the survival of the system from the long-term view. The management function carries out planning and controlling the overall activities for the other four functions in order to run the system. Finally it discuses implications for the diagnosis and the decision making process of S&T policy.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2002.03a
• /
• pp.125-132
• /
• 2002

In this study, a numerical method is developed for nonlinear analysis for soil-pile-structure interaction system in time domain. Finite elements considering material nonlinearity are used for the near field and boundary elements for the far field. In the near field, frame elements are used for modeling a pile and plane-strain elements for surrounding soil and superstructure. In. the far field, boundary element formulation using the dynamic fundamental solution is adopted and coupled with the near field. Transformation of stiffness matrices of boundary elements into time domain is performed by inverse FFT. Stiffness matrices in the near field and far field are coupled. Newmark direct time integration method is applied. Developed soil-pile-structure interaction analysis method is verified with available literature and commercial code. Also, parametric studies by developed numerical method are performed. And seismic response analysis is performed using actual earthquake records.