• 산업경영시스템학회지
• /
• 제38권4호
• /
• pp.11-21
• /
• 2015

In order to achieve success in ground operations, searching for moving targets is one of critical factors. Usually, the system of searching for adversary ground moving targets has complex properties which includes target's moving characteristics, camouflage level, terrain, weather, available search time window, distance between target and searcher, moving speed, target's tactics, etc. The purpose of this paper is to present a practical quantitative method for effectively searching for infiltrated moving targets considering aforementioned complex properties. Based upon search theories, this paper consists of two parts. One is infiltration route analysis, through terrain and mobility analysis. The other is building dynamic probability maps through Monte Carlo simulation to determine the prioritized searching area for moving targets. This study primarily considers ground moving targets' moving pattern. These move by foot and because terrain has a great effect on the target's movement, they generally travel along a constrained path. With the ideas based on the terrain's effect, this study deliberately performed terrain and mobility analysis and built a constrained path. In addition, dynamic probability maps taking terrain condition and a target's moving speed into consideration is proposed. This analysis is considerably distinct from other existing studies using supposed transition probability for searching moving targets. A case study is performed to validate the effectiveness and usefulness of our methodology. Also, this study suggests that the proposed approach can be used for searching for infiltrated ground moving target within critical time window. The proposed method could be used not only to assist a searcher's mission planning, but also to support the tactical commander's timely decision making ability and ensure the operations' success.

• Interaction and multiscale mechanics
• /
• 제5권3호
• /
• pp.287-318
• /
• 2012

We apply a partitioned-solution (iterative-staggered) coupling method based on a fixed Eulerian mesh with the level set function to a large-deformation fluid-structure interaction (FSI) problem where a large-deformable thin structure moves in a high-speed flow field, as an airbag does during deployment. This method combines advanced fluid and structure solvers-specifically, the constrained interpolation profile finite element method (CIP-FEM) for fluid Eulerian mesh and large-deformable structural elements for Lagrangian structural mesh. We express the large-deformable interface as a zero isosurface by the level set function, and introduce virtual nodes with level sets and structural normal velocities to generate the level set function according to the large-deformable interfacial geometry and enforce the kinematic condition at the interface. The virtual nodes are located in the direction normal to the structural mesh. It is confirmed that application of the method to unfolded airbag deployment simulation shows the adequacy of the method.

• 대한기계학회논문집A
• /
• 제28권12호
• /
• pp.1950-1957
• /
• 2004

Analysis for structures composed of materials containing regularly spaced in-homogeneities is usually executed by using averaged material properties. In order to evaluate the effective properties, a unit cell is defined and loaded somehow, and its response is investigated. The imposed loading, however, should accord to the status of unit cells immersed in the macroscopic structure to secure the accuracy of the properties. In this study, mathematical description for the periodicity of the displacement field is derived and its direct implementation into FE models of unit cell is attempted. Conventional finite element code needs no modification, and only the boundary of unit cell should be constrained in a way that the periodicity is preserved. The proposed method is applicable to skew arrayed in-homogeneity problems. Homogenized in-plane elastic properties are evaluated for a few representative cases and the accuracy is examined.

• 한국소음진동공학회논문집
• /
• 제20권8호
• /
• pp.761-766
• /
• 2010

The goal of this study is to analysis natural frequency for different static postures of human leg. To perform this research human leg is modeled by multi-body modeling for the musculoskeletal system. This leg model has biarticular muscles which acting on two joints and the muscles represents some of the major muscles, such as hamstring, of the upper and lower limbs. To obtain each static equilibrium position energy method is employed and to analysis natural frequency linearization method for constrained mechanical system is employed. Static equilibrium position depends on some parameter or condition such as hamstring stiffness or external force. Making a change these parameter the aim of this research can be performed.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2005년도 춘계학술대회논문집
• /
• pp.92-95
• /
• 2005

In this study, Heavy-weight floor impact sound and vibration in concrete structures with different slab thickness have been measured in a test building. It was found that natural frequency increased according to increases of slab thickness, and acceleration level decreases. Results also show that the measurements in the 210 and 240mm slab structures are complied with the result from finite element analysis but the In and 180mm slab structures are not because the structures are constrained to the ground. Therefore, in modelling process the condition of sub-structures should be examined in relation to the boundary conditions.

• 전기학회논문지
• /
• 제57권10호
• /
• pp.1708-1712
• /
• 2008

This paper describes a linear matrix inequality (LMI) approach to the design of robust low-order power system stabilizers (PSSs), which are used to damp out local-mode oscillations of synchronous generators. The performance of a PSS is expressed as the location of the closed-loop poles, and a single fixed-gain pole-placement controller is synthesized for a wide range of operating conditions. The synthesis results in simultaneous regional pole-placement stabilization. and is formulated as an LMI feasibility problem with a rank condition. A penalty method is applied to solve the rank-constrained LMI problem. Numerical experiments with a single-machine connected to an infinite bus system were performed to demonstrate the proposed method.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제53권11호
• /
• pp.747-752
• /
• 2004

This paper presents an iterative linear matrix inequality (LMI) approach to the design of a static output feedback (SOF) stabilization controller. A linear penalty function is incorporated into the objective function for the non-convex rank constraint so that minimizing the penalized objective function subject to LMIs amounts to a convex optimization problem. Hence, the overall procedure results in solving a series of semidefinite programs (SDPs). With an increasing sequence of the penalty parameter, the solution of the penalized optimization problem moves towards the feasible region of the original non-convex problem. The proposed algorithm is, therefore, convergent. Extensive numerical experiments are Deformed to illustrate the proposed algorithm.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제55권5호
• /
• pp.226-228
• /
• 2006

This paper deals with a linear matrix inequality (LMI) approach to the design of a static output feedback controller that simultaneously stabilizes a finite collection of linear time-invariant plants. Simultaneous stabilization by static ouput feedback is represented in terms of LMIs with a rank condition. An iterative penalty method is proposed to solve the rank-constrained LMI problem. Numerical experiments show the effectiveness of the proposed algorithm.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 하계학술대회 논문집 A
• /
• pp.28-30
• /
• 2000

This paper introduces a power flow model of SSSC for voltage stability study. The SSSC model is obtained from the injection model of voltage source inverter by adding the condition that SSSC injection voltage is in quadrature with current of SSSC-installed branch. This model is incorporated into modified CPF algorithm to study effects of SSSC on the security-constrained interface flow limit. Determination of interface flow limit is simply briefed. In case study a 771-bus real system is used to show that SSSC can improve interface flow limit in terms of voltage stability.

• 한국경영과학회지
• /
• 제15권1호
• /
• pp.73-82
• /
• 1990

This paper describes two algorithms to Nonlinear programming problems with equality constraints and with equality and inequality constraints. The first method treats nonlinear programming problems with equality constraints. Utilizing the nonlinear programming problems with equality constraints. Utilizing the nonlinear parametric programming technique, the method solves the problem by imbedding it into a suitable one-parameter family of problems. The second method is to solve a nonlinear programming problem with equality and inequality constraints, by minimizing a square sum of nonlinear functions which is derived from the Kuhn-Tucker condition.