• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.186-188
• /
• 2004

This paper describes the feasibility study of HVDC system application to KEPCO power system for increasing power transfer capability or the flexibility of power delivery from one area to the other using the existing transmission line. This paper assumes the 345kV transmission line connecting between Shinokchun and Sedaegu to be converted to the DC line by replacing the AC insulator with that of DC. Then, the HVDC bipole system of 1000MVA with $\pm300kV$ is designed and the contingency studies are carried out.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.40 no.3
• /
• pp.1-21
• /
• 2015

Customer firms exercise various sources of power to influence their suppliers' behaviors or decisions. In this study we aim to examine the effects of customers' sources of power on their supplier's performance improvement. This study posits that a customer's expert, referent, and reward power positively influence a supplier's performance directly as well as indirectly through increased supplier-customer integration. On the contrary, the customer's coercive power is expected to worsen the supplier's operational performance because of increasing distrust, dissatisfaction, and conflict with the customer. Data collected from 1,229 firms from Korea, China, Hong Kong, Taiwan, and the U.S. are used to test the hypotheses. Expert power proves to be the most effective source of customer power in improving a supplier's inventory cost, delivery, and flexibility performance. In contrast, coercive power deteriorates significantly all supplier performance variables. Academic and managerial implications are presented and future research directions are also discussed.

• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.712-714
• /
• 2005

With rapid growth of industry, underground power delivery systems are growing so rapidly and its capacity also growing. So if there are any accident in underground power cable, its inference is too great to count. So power system operators should find Its fault location as soon as possible and replace it But it is difficult to find its fault location for underground power cable. We are developing fault location system for underground power cable which can detect its fault location exactly. This system usually monitor underground power cable on-line But if there are an accident, it record Its transient signal and we can calculate fault location by analyzing it. To develop fault location system for power cable, we needed fault simulation system and we installed it physically and tested at various point. in this thesis, we describe on signal processing technology to detect fault location on power cable and on the result of tested fault location performance.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.19 no.11
• /
• pp.1055-1060
• /
• 2006

High temperature superconducting(HTS) power cable is expected to be used for power transmission lines supplying electric power for densely populated cities in the near future. Since HTS power cable is capable of the high current density delivery with low power loss, the cable size can be compact comparing with the conventional cable whose capacity is same. In this paper, the authors propose the real time simulation method which puts a teal HTS wire into the simulated 22.9 kV utility grid system using Real Time Digital Simulator (RTDS). For the simulation analysis, test sample of HTS wire was actually manufactured. And the transient phenomenon of the HTS wire was analyzed in the simulated utility power grid. This simulation method is the world first trial in order to obtain much better data for installation of HTS power device into utility network.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.17 no.5
• /
• pp.416-422
• /
• 2012

This paper proposes a low power-loss current measurement using a resistor and bypass switch. Conventional current sensing method using a resistor has a disadvantage of power loss which degrades the efficiency of the entire systems. On the other hand, proposed measurement technique operating with bypass-switch connected in parallel with sensing resistor can reduce power loss significantly the current sensor. The propose measurement works for discrete-time sampling of current sensing. Even while the analog-digital conversion does not occur at the controller, the sensing voltage across the sensor still causes ohmic conduction loss without information delivery. Hence, the bypass switch bypasses the sensing current with a small amount of power loss. In this paper, a 90[W] prototype hardware has been implemented for photovoltaic MPPT experimental verification of the proposed low power-loss current measurement technique. From the results, it can be seen that PV power observation is successfully done with the proposed method.

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.1328-1333
• /
• 2007

Unpredictable customer demands make manufacturers to make quality products with cheaper price and shorter delivery. To survive in the global market, the manufacturing industry needs to equip with advanced technologies including IT. Under this situation, "collaboration"is the best solution for manufacturers to survive and to grow their company instead of competition. With this strategy, we have conducted a project(e-Manufacturing). The companies participate to the project attained the amazing results by utilizing collaboration systems such as delivery shortened and increase in sale/profit. Since the strategy of the project is assessed to be very useful to increase competition power of manufacturers, the project will be enlarged to cover wider application domains with a new project name called "i-Manufacturing". In this paper, therefore, we introduce the specific output from the e-Manufacturing project and the specific strategies/plans of i-Manufacturing project.

• The Journal of Information Systems
• /
• v.13 no.2
• /
• pp.155-172
• /
• 2004

The purpose of this study is to investigate factors which can lead small buyers to participate in a Reverse Aggregation Electronic Market (RAEM). Five factors including search, selection, price, delivery, and Internet literacy were selected as possible factors which are expected to influence small buyers' participation in a RAEM. This paper focused on a RAEM of the Korean automotive industry in which the third party aggregator formed a group of small automobile repair shops (ARS) and amassed buying power for them by building a buyer' oriented electronic market (EM). Survey data were collected from small ARS in South Korea. The results of the empirical analysis indicated that fast delivery and support for Internet illiteracy are potential incentives that could influence buyers' decisions to join a RAEM.

• Journal of Construction Engineering and Project Management
• /
• v.4 no.3
• /
• pp.21-32
• /
• 2014

The practiced conventional methods for maintenance management in Malaysian Polytechnic faced many issues due to poor service delivery, inadequate finance, poor maintenance plan and maintenance backlogs. The purpose of this study is to improve the conventional method practices which tend to be ineffective in Malaysian Polytechnic. The case studies were conducted with eight Polytechnics and are selected based on conventional method practices and its major problems. There are around 32 Polytechnics in Malaysia and almost are using conventional methods. The number is considered very big indicating that the use of modern Information and Communication Technology (ICT) is still very limited compared to other institutions of higher learning in Malaysia. The overall findings of this research indicated; poor service delivery, inadequate financial, poor maintenance planning and maintenance backlogs. There is also need to overcome less man power competencies of maintenance management practices which existed with all eight Polytechnics. The proposed system is intended to be used for maintenance management practices at Malaysian Polytechnics in order to provide high-quality of building facility with safe and healthy environments.

• Proceedings of the KIEE Conference
• /
• 2001.07a
• /
• pp.270-272
• /
• 2001

This paper deals with the analytical approach for the reliability assessment in radially operated distribution systems. The approach can estimate the expected reliability performance of distribution systems by a direct assessment of the configuration of the systems using the reliability indexes such as NDP(Non-Delivery Power) and NDE(Non-Delivery Energy). The indexes can consider the number and configuration of the load, but can not consider the characteristics of the load which is the one of the most important factor in the investment cost for the distribution systems. Therefore, This paper presents the new indexes considering the expected interruption cost for the load section and shows the effectiveness by simulating at the model systems.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.12
• /
• pp.2179-2185
• /
• 2008

This paper deals with the optimal investment method for distribution facilities, based on the analytical approach for the reliability assessment in distribution systems interconnected with new dispersed generations. The existing approach can estimate the expected reliability performance of distribution systems by a direct assessment of the configuration of the systems using the reliability indexes such as NDP(Non-Delivery Power) and NDE(Non-Delivery Energy). The indexes can only consider the number and configuration of the load, but can not consider the characteristics of the load which is the one of the most important factor in the investment cost for the distribution systems. Therefore, this paper presents the new performance indexes for the investment of the distribution facilities considering both the expected interruption cost for the load section and the operation characteristics of dispersed generations. The results from a case study show that the proposed methods can be a practical tool for the voltage management in distribution systems including dispersed sources.