• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.3
• /
• pp.451-456
• /
• 2007

This paper presents a problem that reconfigure distribution power system using branch exchange method. Optimal reconfiguration problem calculates line loss, voltage condition about system states of all situations that become different according to line On/off status, and search for optimum composition of these. However, result is difficult to be calculated fast. Because radiated operation condition of system is satisfied using many connection and sectionalize switches in the distribution power system. Therefore, in this paper, optimization method for reducing system total loss and satisfying operating condition of radial and constraints condition of voltage is proposed using the fastest branch exchange. And optimal solution at branch exchange algorithm can be wrong estimated to local optimal solution according to initial operating state. Considering this particular, an initial operating point algorithm is added and this paper showed that optimal solution arrives at global optimal solution.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2004.11a
• /
• pp.229-232
• /
• 2004

This paper is about the new Distribution System of the electric customers. The Power loss in the Distribution System is disregarded and rarely managed so far. But, economically, this loss is not small quantity to Ignore. So, in this paper, we suggest that the new Distribution System of the electric customer by simply changing the locations of Power Transformer and other power facilities which is located inside of the customer. And we also show that the Power loss is decreased with this systematic changing by approximated calculation.

• Proceedings of the KIEE Conference
• /
• 2000.11a
• /
• pp.61-63
• /
• 2000

As increasing the failure of distribution transformers, we need to manage them efficiently. This paper proposes the method for distribution transformer's management using loss-of-life calculation. The Data Acquisition System(DAS) was developed to manage transformers and the HDLC protocol applied to the system. It will be feasible application to diagnose distribution transformers by checking load conditions such as top oil temperature, ambient temperature, load current, etc. and using loss-of-life calculation.

• Proceedings of the KIEE Conference
• /
• 1999.07c
• /
• pp.1459-1461
• /
• 1999

Distribution systems is consist of network in physical aspect, and radial in electrical aspect. Therefore, radial operation is realized by changing the status of sectionalizing switches, and is usually done for loss reduction in the system. In this paper, we propose a optimal method for distribution systems reconfiguration. Specifically, we use K-optimal algorithm and tabu search method to solve distribution systems reconfiguration for loss minimization problem.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.11b
• /
• pp.114-117
• /
• 2005

In the reactive concentric resonator, perforated inner tubes are widely used for various purposes related to noise reduction, flow guiding, and structural aspects. Perforation distribution patterns influence both the acoustic performance and mechanical performance. In this study, the influence of distribution patterns on acoustic performance are explained by adopting the concept of extended inlet/outlet length. Predicted transmission with varying extended inlet/outlet length is compared with prediction by varying distribution patterns. The transmission loss difference due to perforation distribution patterns can be explained by changing the extended inlet/outlet length of the uniformly perforated resonator.

• Proceedings of the KIEE Conference
• /
• 2001.11b
• /
• pp.330-332
• /
• 2001

Distribution systems is consist of network in physical and radial in electrical aspect. Therefore radial operation is realized by changing the status of sectionalizing switches, and is usually done for loss reduction in the system. In this paper, we propose a optimal method for distribution systems reconfiguration. Specifically we use genetic algorithm method to solve distribution systems reconfiguration for loss minimization problem. A genetic algorithm(GA) is set up, in which some improvements are made on string coding, fitness function and mutation pattern. As a result, premature convergence is avoided.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.49 no.3
• /
• pp.118-123
• /
• 2000

This paper presents an efficient algorithm for loss reduction and load balancing by sectionalizing switch operation in large scale distribution system of radial type. We use Genetic algorithm and Kruskal algorithm to solve distribution system reconfiguration. Genetic algorithm is used to minimize objective function including loss and load balancing items. Kruskal algorithm is used to satisfy the radial condition of distribution system. The experimental results show that the proposed method has the ability to search a good solution regardless of initial configuration and size of system.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.50 no.4
• /
• pp.188-196
• /
• 2001

This paper presents and efficient algorithm for the loss minimization by automatic sectionalizing switch operation in distribution systems. Ant colony algorithm is multi-agent system in which the behaviour of each single agent, called artificial ant, is inspired by the behaviour of real ants. Ant colony algorithm is suitable for combinatiorial optimization problem as network reconfiguration because it use the long term memory, called pheromone, and heuristic information with the property of the problem. The proposed methodology with some adoptions have been applied to improve the computation time and convergence property. Numerical examples demonstrate the validity and effectiveness of the proposed methodology using a KEPCO's distribution system.

• Journal of Integrative Natural Science
• /
• v.5 no.3
• /
• pp.186-189
• /
• 2012

For the mean vector of a p-variate normal distribution ($p{\geq}3$), the optimal estimation within the class of James-Stein type decision rules under the quadratic loss are given when the underlying distribution is that of a variance mixture of normals and when the norm ${\parallel}\underline{{\theta}}{\parallel}$ in known. It also demonstrated that the optimal estimation within the class of Lindley type decision rules under the same loss when the underlying distribution is the previous type and the norm ${\parallel}{\theta}-\overline{\theta}\underline{1}{\parallel}$ with $\overline{\theta}=\frac{1}{p}\sum\limits_{i=1}^{n}{\theta}_i$ and $\underline{1}=(1,{\cdots},1)^{\prime}$ is known.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2003.09b
• /
• pp.45-48
• /
• 2003

We propose some properties of Bayesian fuzzy hypotheses testing by revision for prior possibility distribution and posterior possibility distribution using weighted fuzzy hypotheses H$\sub$0/($\theta$) versus H$_1$($\theta$) on $\theta$ with loss function.