• 대한전기학회논문지:전력기술부문A
• /
• 제51권11호
• /
• pp.551-558
• /
• 2002

This paper describes an optimal power flow algorithm considering environmental constraints. In this algorithm, we use the costate method, concepts of fictitious generator, variable reduction and effective constraint for the effective linear programming application. Especially we consider environmental constraints. The proposed method is applied to IEEE RTS-30 model system, 24 and 96 Reliability Test Systems and the results shows the effectiveness of the method.

• 대한전자공학회논문지SD
• /
• 제37권9호
• /
• pp.66-77
• /
• 2000

이 논문에서는 Best Imaginary Level-Iterative(BILI) 분할 방법이라 부르는 새로운 하드웨어/소프트웨어 분할 알고리즘을 제안하다. 이 분할 알고리즘은 여러 개의 하드웨어와 소프트웨어로 이루어진 시스템에 대해서 분할을 할 수 있을 뿐만 아니라, 여러 가지의 구현 가능성 중에서 적은 비용의 구현을 선택하는 문제까지 해결한다. 이 분할 알고리즘은 기존의 분할 알고리즘인 GCLP와 비교하여 약 15%의 비용 감소를 가지고, 항상 최적의 해를 찾는 장수 선형 프로그래밍과 비교하여 약 5%정도의 비용 증가를 가진다.

• 대한산업공학회지
• /
• 제21권4호
• /
• pp.541-553
• /
• 1995

An efficient algorithm is proposed for a buffer allocation in a continuous flow line. The problem is formulated as a non-linear programming with linear constraints. The concept of pseudo gradient and gradient projection is employed in developing the algorithm. Numerical experiments show that the algorithm gives the actual optimal solutions to the problems with single linear constraint limiting the total buffer capacity. Also, even in longer production lines, it gives quite good solutions to the problems with the general linear resource constraints within a few seconds.

• Ocean Systems Engineering
• /
• 제5권2호
• /
• pp.91-107
• /
• 2015

Ship hull optimization is categorized as a bound, multi variable, multi objective problem with nonlinear constraints. In such analysis, where the objective function representing the performance of the ship generally requires computationally involved hydrodynamic interaction evaluation methods, the objective functions are not smooth. Hence, the evolutionary techniques to attain the optimum hull forms is considered as the most practical strategy. In this study, a parametric ship hull form represented by B-Spline curves is optimized for multiple performance criteria using Genetic Algorithm. The methodology applied to automate the hull form generation, selection of optimization solvers and hydrodynamic parameter calculation for objective function and constraint definition are discussed here.

• Communications for Statistical Applications and Methods
• /
• 제12권2호
• /
• pp.443-451
• /
• 2005

The studied in this paper is a new algorithm for searching the maximum likelihood estimate(MLE) in which probability density function is not explicitly expressed. Newton-Raphson's root-finding routine and a nonlinear numerical optimization algorithm with constraint (so-called feasible sequential quadratic programming) are used. This algorithm is applied to the Wakeby distribution which is importantly used in hydrology and water resource research for analysis of extreme rainfall. The performance comparison between maximum likelihood estimates and method of L-moment estimates (L-ME) is studied by Monte-carlo simulation. The recommended methods are L-ME for up to 300 observations and MLE for over the sample size, respectively. Methods for speeding up the algorithm and for computing variances of estimates are discussed.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집(한일합동학술편); 한국과학기술대학, 충남; 16-17 Oct. 1987
• /
• pp.882-885
• /
• 1987

The path of an industrial manipulator in a crowded workspace generally consists of 8 set of Cartesian straight line path connecting a set of two adjacent points. To achieve the Cartesian straight line path is, however, a nontrivial task and an alternative approach is to place enough intermediate points along a desired path and linearly interpolate between these points in the joint space. A method is developed that determines the subtravelling- and the transition-time such that the total travelling time for this path is minimized subject to the maximum joint velocities and accelerations constraint. The method is based on the application of nonlinear programming technique, i.e., FTM (Flexible Tolerance Method). These results are simulated on a digital computer using a six-joint revolute manipulator to show their applications.

• 한국경영과학회지
• /
• 제39권1호
• /
• pp.113-127
• /
• 2014

The stochastic dominance approach is to form a portfolio that stochastically dominates a predetermined benchmark portfolio such as KOSPI. This study is to search a set of portfolio weights for the first-order stochastic dominance with maximum utility defined in terms of mean and variance by managing the constraint set and the objective function in an iterative manner. A nonlinear programming algorithm was developed and tested with promising results against Korean stock market data sets.

• International Journal of Aeronautical and Space Sciences
• /
• 제12권3호
• /
• pp.288-295
• /
• 2011

This paper addresses minimum-fuel, two-dimensional trajectory optimization for a soft lunar landing from a parking orbit to a desired landing site. The landing site is usually not considered when performing trajectory optimization so that the landing problem can be handled. However, for precise trajectories for landing at a desired site to be designed, the landing site has to be considered as the terminal constraint. To convert the trajectory optimization problem into a parameter optimization problem, a pseudospectral method was used, and C code for feasible sequential quadratic programming was used as a numerical solver. To check the reliability of the results obtained, a feasibility check was performed.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2004년도 ICCAS
• /
• pp.1769-1775
• /
• 2004

In presence of collision between two rigid bodies, they exhibit impulsive behavior to generate physically feasible state. When the frictional impulse is involved, collision resolution can not be easily made based on a simple Newton's law or Poisson's law, mainly due to possible change of collision mode during collision, For example, sliding may change to sticking, and then sliding resumes. We first examine two conventional methods: the method of mode evolution by differential equation, and the other by linear complementarity programming. Then, we propose a new method for mode evolution by solving only algebraic equations defining mode changes. Further, our method attains the original nonlinear impulse cone constraint. The numerical simulation will elucidate the advantage of the proposed method as an alternative to conventional ones.

• 대한산업공학회지
• /
• 제28권1호
• /
• pp.105-111
• /
• 2002

When transporting multiple items by trucks of various size, one needs to assign a group of items to each truck so as to minimize the total cost, while meeting the weight and volume constraint of each truck. In this paper, we formulate the problem as an integer programming problem and propose four heuristic algorithms for the problem. Computer simulation is used to evaluate the average performance of the four heuristic algorithms for the consolidated transportation problem.