• 대한기계학회논문집A
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• 제20권1호
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• pp.35-43
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• 1996

A computer program for automatic deriving the symbolic equations of motion for robots using the programming language MATHEMATICA has been developed. The program, developed based on the Lagrange formalism, is applicable to the closed chain robots as well as the open chain robots. The closed chains are virtually cut open, and the kinematics and dynamics of the virtual open chain robot are analyzed. The constraints are applied to the virtually cut joints. As a result, the spatial closed chain robot can be considered as a tree structured open chain robot with kinematic constraints. The topology of tree structured open chain robot is described by a FATHER array. The FATHER array of a link indicates the link that is connected in the direction of base link. The constraints are represented by Lagrange multipliers. The parallel robot, DELTA, having three-dimensional closed chains is modeled and simulated to illustrate the approach.

• 대한기계학회논문집A
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• 제29권12권
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• pp.1629-1637
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• 2005

Optimum sensitivity analysis (OSA) is the process to find the sensitivity of optimum solution with respect to the parameter in the optimization problem. The prevalent OSA methods calculate the optimum sensitivity as a post-processing. In this research, a simple technique is proposed to obtain optimum sensitivity as a result of the original optimization problem, provided that the optimum sensitivity of objective function is required. The parameters are considered as additional design variables in the original optimization problem. And then, it is endowed with equality constraints to penalize the additional variables. When the optimization problem is solved, the optimum sensitivity of objective function is simultaneously obtained as Lagrange multiplier. Several mathematical and engineering examples are solved to show the applicability and efficiency of the method compared to other OSA ones.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1375-1381
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• 2007

In this paper, we propose a linear modeling and identical PD controller design scheme for the three-pole hybrid-type AMB recently developed in the laboratory, which consists of three permanent magnets, providing bias flux, three Hall diodes, measuring rotor displacements, and ring type permanent magnet bearing, stabilizing in axial and tilting directions. Along the three physical coordinates formed by three poles, we introduce the redundant coordinate system and three identical decoupled controllers to construct linear model. The experiments are also carried out in order to verify the effectiveness of proposed controller in stabilizing the transient and steady state response of rotor.

• 한국멀티미디어학회논문지
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• 제5권3호
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• pp.249-254
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• 2002

본 논문에서는 영상압축을 위한 버퍼제약에 의한 적응양자화 알고리즘에 대해서 논하고져 한다. 버퍼제약에 의한 알고리즘은 source coding과 더불어 그간 연구되다가, 최근에는 비트율 왜곡의 이름으로 연구가 더욱 진전돼 오고 있다. 여기에서 우리는 버퍼 occupancy의 값이 비트율 왜곡의 측정치에서 Lagrange multiplier 형식으로 통합되는 것을 제안한다. 여기서 제안하는 알고리즘이 Viterbi 알고리즘과는 반대로 최적치에는 약간 못미치는 성능을 보여주지만, 대신 계산의 복잡도가 매우 낮을 뿐 아니라, 버퍼 제어 알고리즘의 안정도를 Liapnov의 안정화이론을 이용해서 간단하게 설명 할 수 있다는 것이다.

• 한국소음진동공학회논문집
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• 제21권3호
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• pp.271-279
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• 2011

In this study, the dynamic analysis of a beam is analyzed by using the finite element method when the beam has moving mass and axial load. To consider the contact force between the moving mass and beam, coupled nonlinear equations of contact dynamics are derived, and then the weak form for the finite element method is established. The finite element computer programs based on the Lagrange multiplier method are developed to compute the contact force. Furthermore, a variety of simulations are performed for various design parameters such as moving mass velocity, compressive axial load and tension load. Finally, relations between the dynamic response and contact force are also discussed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.15-17
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• 2004

The flexible AC transmissions system (FACTS) is the underpinning concept upon which are based promising means to avoid effectively power flow bottlenecks and ways to extend the loadability of existing power transmission networks. This paper proposes a method by which the optimal locations of the FACTS to be installed in power system under cost function. The optimal solution of this type of problem requires large scale nonlinear optimisation techniques. We used Lagrange multipliers to solve a nonlinear equation with equality and ineaquality constraints. Case studies on the standard IEEE 14 bus system show that the method can be implemented successfully and that it is effective for determining the optimal location of the FACTS

• Journal of Advanced Marine Engineering and Technology
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• 제24권3호
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• pp.106-112
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• 2000

Since the oil crisis, we have been concerned about the energy saving techniques of electric generating systems. As a part of the effort to save energy, automatic electric load sharing device was developed. Usually, ship's electric generating system consists of two or three sets of generator. And, electric generating system is operated as single or parallel operation mode according to the demanded electric power. Therefore, it is important to investigate generators operating mode for the supply of required electric power in the ship in order to decrease the operating cost. So, this paper suggests the method to solve the optimal electric load distribution problem by dynamic programming. And, this thesis indicates that the proposed method is superior to the lagrange multiplier's method in obtaining optimal load distribution solution in the ship's electric generating system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1993년도 춘계학술대회논문집; 한국과학연구소, 21 May 1993
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• pp.52-56
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• 1993

An efficient method is presented for determining transient responses of locally nonlinear structures using substructure eigenproperties and Lagrange multiplier technique. The method is based upon the mode synthesis formulation procedure, but does not construct the equations of motion of the combined whole structure compared with the conventional methods. For modal bases of each linear substructure, either fixed or free interface modes can be employed. The transient analysis is based upon the recurrence discrete-time state equations and offers the simplicity of the Euler integration method without requiring small time increment and iterative solution procedure. Numerical examples reveal that the method is very accurate and efficient in calculating transient responses compared with the direct numerical integration method.

• 한국음향학회지
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• 제15권2호
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• pp.33-39
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• 1996

비선형 건마찰 감쇠를 가진 외팔보의 강제진동 응답을 건마찰 감쇠기와 가진력의 위치변화에 대하여 미끄러진 변위와 힘레벨을 수치해석하였다. 구성모드의 분석은 비선형 감쇠를 가진 계를 해석하기 위해 구속조건과 Lagrange 승수에 기초를 두고 분석하였다. 외팔보의 진동분석 결과 건마찰 감쇠기가 부착된 단순 지지된 보(beam)에서 보여진 응답특성과 유사한 특성이 나타났다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.464-469
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• 2005

Optimum sensitivity analysis (OSA) is the process to find the sensitivity of optimum solution with respect to the parameter in the optimization problem. The prevalent OSA methods calculate the optimum sensitivity as a post-processing. In this research, a simple technique is proposed to obtain optimum sensitivity as a result of the original optimization problem, provided that the optimum sensitivity of objective function is required. The parameters are considered as additional design variables in the original optimization problem. And then, it is endowed with equality constraints to penalize the additional variables. When the optimization problem is solved, the optimum sensitivity of objective function is simultaneously obtained as Lagrange multiplier. Several mathematical and engineering examples are solved to show the applicability and efficiency of the method compared to other OSA ones.