• Journal of electromagnetic engineering and science
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• v.13 no.4
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• pp.233-239
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• 2013

This paper proposes an accurate approach for predicting transferred power from a noise source to integrated circuits based on the characteristics of the power transfer network. A power delivery trace on a package and a printed circuit board are designed to transmit power from an external source to integrated circuits. The power is demonstrated between an injection terminal on the edge of the printed circuit board and integrated circuits, and the power transfer function of the power distribution network is derived. A two-tier calibration is applied to the test, and scattering parameters of the network are measured for the calculation of the power transfer function. After testing to obtain the indispensable parameters, the real received and tolerable power of the integrated circuits can be easily achieved. Our proposed estimation method is an enhancement of the existing the International Electrotechnical Commission standard for precise prediction of the electromagnetic immunity of integrated circuits.

• Journal of Korea Water Resources Association
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• v.36 no.1
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• pp.105-115
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• 2003

The computation model which evaluates combined hydraulic and mechanical reliability, is developed to analyze the integrated reliability in water distribution system. The hydraulic reliability is calculated by considering uncertain variables like water demand, hydraulic pressure, pipe roughness as random variables according to proper distribution type. The mechanical reliability is evaluated by analyzing the effect of pipe network with sequential failure of network components. The result of this study model applied to the real pipe network shows that this model can be used to simulate the uncertain factors effectively in real pipe network. Therefore, The pipe-line engineers can design and manage the network system with more quantitative reliability, through applying this model to reliable pipe network design and diagnosis of existing systems.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.2
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• pp.110-120
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• 2010

In this paper, we propose a tunable SIW(Substrate Integrated Waveguide) using dielectric screws for eliminating the phase imbalance of large size power distribution networks(PDN). Alumina screws partially inserted into several through holes of the tunable SIW section effectively change the phase shift without S-parameter degradation. ${\pm}33.9^{\circ}$ measured phase imbalance of a large conventional 9 GHz SIW-PDN of $370\;mm{\times}195\;mm$ size has been greatly reduced to ${\pm}4.65^{\circ}$. We expect that the proposed tunable SIW plays an important role for a light-weight, high performance substrate integrated phased array system(Si-PAS) and large size SIW circuit applications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.1034-1041
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• 2007

This paper presents the developing results of improved distribution automation system including system configuration and subsystem design, prototype hardware and software implementation, and pilot tests on the real distribution networks of Korea Electric Power Corporation (KEPCO). An integrated system is designed to combine independent system for the distribution field works with DAS; transformer monitoring, power quality monitoring, voltage monitoring, outage monitoring, etc. The communication network is hierarchically configured as main network and branch network and well-defined integrated terminal units were developed. In addition, useful host configuration and applications were developed to integrate the services with DAS or interfacing other systems. Pilot tests were performed to verify that the system enables to properly integrate the DAS and other services of the distribution network.

• IE interfaces
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• v.12 no.2
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• pp.222-236
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• 1999

This paper presents a design and implementation of an intelligent-integrated production-logistics systems. The situation considered here is that there are multiple manufacturing plants and multiple distribution centers. Effective distribution resource and production planning are required to reduce inventory cost and to avoid inventory shortage. We propose an intelligent forecasting scheme of each distribution centers, adaptive inventory replenishment planning, distribution resource planning, and integrated production planning system. In forecasting a huge number of on-line model identification is performed using neural network approximation capability. An efficient adaptive replenishment planning and distribution resource planning are also presented in connection with forecasting scheme. An appropriate production is also requested based on production lead-time and the results of distribution planning. Experimental simulations are presented to verify the proposed approach using real data.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.8
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• pp.1463-1471
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• 2009

In this paper, a new algorithm of Integrated Volt/Var Control (IVVC) is proposed using Volt/Var control for the Distribution Automation System (DAS) based on the modeling of the distributed load and the distributed current. In the proposed, the load flow based on the modeling of the distributed load and the distributed current are estimated from constants of four terminals using the measurement of the current and power factor from a Feeder Remote Terminal Unit (FRTU). For Integrated Volt/Var Control (IVVC), the gradient method is applied to find optimal solution for tap and capacity control of OLTC (On-Load Tap Changers), SVR (Step Voltage Regulator), and SC (Shunt Condenser). What is more Volt/Var control method is proposed using moving the tie switch as well as IVVC algorithm using power utility control. In the case studies, the estimation and simulation network have been testified in Matlab Simulink.

• Journal of Communications and Networks
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• v.14 no.5
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• pp.554-565
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• 2012

In this paper, we study a cross-layer and end-to-end optimization problem for the integrated wireless and wireline network that consists of one wireline core network and multiple wireless access networks. We consider joint end-to-end flow control/distribution at the transport and network layers and opportunistic scheduling at the data link and physical layers. We formulate a single stochastic optimization problem and solve it by using a dual approach and a stochastic sub-gradient algorithm. The developed algorithm can be implemented in a distributed way, vertically among communication layers and horizontally among all entities in the network, clearly showing what should be done at each layer and each entity and what parameters should be exchanged between layers and between entities. Numerical results show that our cross-layer and end-to-end optimization approach provides more efficient resource allocation than the conventional layered and separated optimization approach.

• Journal of the Korea Safety Management & Science
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• v.22 no.4
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• pp.65-74
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• 2020

Many of companies have made significant improvements for globalization and competitive business environment The supply chain management has received many attentions in the area of that business environment. The purpose of this study is to generate realistic production and distribution planning in the supply chain network. The planning model determines the best schedule using operation sequences and routing to deliver. To solve the problem a hybrid approach involving a genetic algorithm (GA) and computer simulation is proposed. This proposed approach is for: (1) selecting the best machine for each operation, (2) deciding the sequence of operation to product and route to deliver, and (3) minimizing the completion time for each order. This study developed mathematical model for production, distribution, production-distribution and proposed GA-Simulation solution procedure. The results of computational experiments for a simple example of the supply chain network are given and discussed to validate the proposed approach. It has been shown that the hybrid approach is powerful for complex production and distribution planning in the manufacturing supply chain network. The proposed approach can be used to generate realistic production and distribution planning considering stochastic natures in the actual supply chain and support decision making for companies.

• KEPCO Journal on Electric Power and Energy
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• v.7 no.1
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• pp.93-99
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• 2021

The government has proposed a mission to enhance intelligent power networks, decrease coal-fired generation, expand distributed energy resources, and promote energy prosumer into the distribution network in Korea. Installation cost of facility expansion to guaranteed interconnection with small distributed energy resources increases dramatically on KEPCO's distribution sector. And it is hard to withdraw in time. In addition, there are explicit research is required to meet the reliability on grid corresponding to the increase of distributed power. Infrastructure support for accommodating energy prosumer is also needed. Therefore, KEPCO is pushing transition to DSO by expanding distribution management scope and changing its roles. In addition, KEPCO is proactively preparing for integrated operation between distribution network and existing distributed power which is accommodated passively. KEPCO is also trying to accept multiple network users, e.g. building platforms, to manage a data and promote new markets. In the long term, transition to DSO will achieve saving investment costs for accommodating distributed sources and maintaining stable electrical quality. And it will be possible to create new business model using the platform to secure revenue.

• Journal of the Korea Safety Management & Science
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• v.22 no.4
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• pp.45-52
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• 2020

Recently, a multi facility, multi product and multi period industrial problem has been widely investigated in Supply Chain Network(SCN). One of keys issues in the current SCN research area involves minimizing both production and distribution costs. This study deals with finding an optimal solution for minimizing the total cost of production and distribution problems in supply chain network. First, we presented an integrated mathematical model that satisfies the minimum cost in the supply chain. To solve the presented mathematical model, we used a genetic algorithm with an excellent searching ability for complicated solution space. To represent the given model effectively, the matrix based real-number coding schema is used. The difference rate of the objective function value for the termination condition is applied. Computational experimental results show that the real size problems we encountered can be solved within a reasonable time.