• 한국공간구조학회논문집
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• 제2권1호
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• pp.75-84
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• 2002

In this study, the 'force density method' for shape finding of cable net structures is presented. This concept is based on the force-length ratios or force densities which are defined for each branch of the net structures. This method renders a simple linear 'analytical form finding' possible. If the free choice of the force densities is restricted by further condition, the linear method is extended to a nonlinear one. The nonlinear one can be applied to the detailed computation of networks. In this paper, the general inverse matrix is introduced to solve the nonlinear equilibrium equation including Jacobian matrix which is rectangular matrix. Several examples for linear and nonlinear analysis applied additional constraints are presented. It is shown that the force density method is suitable for form finding of cable net and the general inverse matrix can be applied to solve the nonlinear equation without Lagrangian factors.

• 전기학회논문지
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• 제58권3호
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• pp.614-620
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• 2009

The force distribution in multi-legged robots is a constrained, optimization problem. The solution to the problem is the set points of the leg contact forces for a particular system task. In this paper, an efficient and general formulation of the force distribution problem is developed using linear programming. The considered walking robot is a quadruped robot with a locked-joint failure, i.e., a joint of the failed leg is locked at a known place. For overcoming the drawback of marginal stability in fault-tolerant gaits, we define safety margin on friction constraints as the objective function to be maximized. Dynamic features of locked-joint failure are represented by equality and inequality constraints of linear programming. Unlike the former study, our result can be applied to various forms of walking such as crab and turning gaits. Simulation results show the validity of the proposed scheme.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 D
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• pp.697-699
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• 2000

In this paper, an extension of model predictive controller for nonlinear process using Takagi-Sugeno(TS) fuzzy model is proposed Since the consequent parts of TS fuzzy model comprise linear equations of input and output variables. it is locally linear, and the Generalized Predictive Control(GPC) technique which has been developed to control Linear Time Invariant(LTI) plants, can be extended as a parallel distributed controller. Also fuzzy soft constraints are introduced to handle both equality and inequality constraints in a unified form. So the traditional constrained GPC can be transferred to a standard fuzzy optimization problem. The proposed method conciliates the advantages of the fuzzy modeling with the advantages of the constrained predictive control, and the degree of freedom is increased in specifying the desired process behavior.

• 제어로봇시스템학회논문지
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• 제5권5호
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• pp.511-520
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• 1999

An anti-reset windup (ARW) based compensation method for state constrained control systems is studied. First, a linear controller is constructed to give a desirable nominal performance ignoring state-constraints of a plant. Then, an additional compensator is introduced to provide smooth performance degradation under state-constraints of the plant. This paper focuses on the effective design method of the additional compensator. By minimizing a reasonable performance index, the proposed compensator is expressed in terms of theplant and ocntroller parameters. The resulting dynamics of the compensated controller exhibits the dominant part of the linear closed-loop system which can be seen from the singular perturbation model reducton theory. THe proposed method guarantees total stability of overall resulting systems if linear controllers were constructed to meet certain condition.

• 한국경영과학회지
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• 제37권4호
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• pp.19-35
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• 2012

The Semantic Web technology, purporting to share, to reuse and to process by machines data stored in the Web environment, incessantly evolves to help human decision making; in particular, decision making based on data, or quantitative decision making. This trend drives researchers to fill the gap with strenuous efforts between the current state of the technology and the terminus of this evolution. The Semantic Web Constraint Language (SWCL) together with SWRL is one of these endeavors to achieve the goal. This paper focuses particularly on how to express the piecewise linear form in the context of SWCL. The importance of this ingredient can be fortified by the fact that any nonlinear expression can be approximated in the piecewise linear form. This paper will also provide the information of how it will work in the decision making process through an example of the Internet shopping mall problem.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.210-215
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• 2004

프로젝트의 계획단계에서 명확한 업무의 정의와 업무간의 상관관계, 자원계획 및 일정계획이 수행되지 않으면, 공사의 진행 시에 많은 변경과 일정 $\cdot$ 비용 상의 문제를 가져올 수 있다. 그래서 본 연구에서는 사례연구를 중심으로 프로젝트 계획단계에서 최적의 소요공기 산정을 위해서 몬테카를로 시뮬레이션과 선형계획법을 적용한 결과, 다음과 같은 결론을 얻었다. 몬테카를로 시뮬레이션을 사용함으로써 각각의 활동이 독립적이고, 프로젝트 소요시간에 대해서 정규분포를 따른다는 가정의 제약조건을 해소함으로 보다 신뢰한 만한 일정 추정이 가능하였으며, 주 경로와 주 경로에 근접한 경로에 신뢰할 만한 일정편차를 계산할 수 있었다. 또한, 선형계획법을 동해서 최적의 소요비용 산정이 가능하였으며, 프로젝트 목표소요공기의 변동에 따른 최적의 목표공기를 산정할 수 있었다.

• Communications for Statistical Applications and Methods
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• 제5권3호
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• pp.581-589
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• 1998

An algorithm is proposed for the $L_1$-estimation with linear equality and inequality constraints in linear regression model. The algorithm employs a linear scaling transformation to obtain the optimal solution of linear programming type problem. And a special scheme is used to maintain the feasibility of the updated solution at each iteration. The convergence of the proposed algorithm is proved. In addition, the updating and orthogonal decomposition techniques are employed to improve the computational efficiency and numerical stability.

• 조명전기설비학회논문지
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• 제21권2호
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• pp.86-93
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• 2007

본 논문은 가용송전용량(ATC)를 계산하기 위한 두 가지 빠른 계산 기법을 제안한다. 이 방법들은 선로의 열적용량한계(Thermal ATC)와 전압 안정도한계(Voltage ATC)를 제약조건으로 ATC를 계산한다. 먼저 선로의 열적용량을 고려한 방법에서는 모선의 전력 변화에 대한 선로의 조류 감도인 PTDF와 n-1 상정사고를 고려한 LODF를 이용하였으며, 전압안정도를 고려한 방법에서는 2모선 등가 시스템을 이용하여 최대 전력을 구하는 방법을 이용하였다. 제안된 방법은 IEEE 30모선 계통에 적용하였으며 그 결과를 다른 방법과 비교하여 제안된 방법의 타당성을 입증하였다.

• 대한수학회지
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• 제21권2호
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• pp.163-172
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• 1984

• Communications for Statistical Applications and Methods
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• 제14권2호
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• pp.281-286
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• 2007

Cook's distance is generalized to the multiple linear regression with linear constraints on regression coefficients. It is used for identifying influential observations in constrained regression models. A numerical example is provided for illustration.