• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.432-437
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• 1998

This paper presents modal characteristics of bowl parts feeder featuring piezoelectric actuators. As wellknown, the piezoelectric materials develop an electric charge proportional to a mechanical stress and vice versa. This generic phenomenon allows us to use the piezoelectric materials as sensors and actuators. Using the actuating property, we can device effective bowl parts feeder. The parts feeder activated by the piezoceramic actuators provides a large degree of freedom of controlling excitation magnitude and frequency, and thus accurate and fast feeding of various parts. As a first phase to demonstrate these advantages, a finite clement model of the bowl parts feeder is constructed and analyzed using commercial software packages. In addition, the simulated modal characteristics are compared with the measured ones to validate the proposed model.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.36-38
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• 1993

This study considers the economic aspect of the distribution automation system, which is the decision-making criteria of the electric utilities for the investment. The feeder automation candidate region is divided into two types of the urban and the rural. The total investment cost of the feeder automation for each type is estimated. The annual cost, is also estimated, by finding the fixed charge rate. To compare the annual cost and the economic effect cost, for the investment decision-making, the costs are quantitatively estimated on the following effects : the manpower replacement, the outage cost saving, the main transformer utilization improvement, the feeder utilization improvement, and the line loss reduction.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.413-419
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• 2004

In these days, 8,000TEU container ship service launches in shipping service at latest based on the economy of scale, unit cost related with ship operation on ocean decreases in proportion to increase of ship scale and mega ship over 10,000TEU is on planning. Most of the exiting researches have performed from the perspective of total operation cost from mega port to mega port. However, the purpose of this paper is to estimate economic efficiency by ports selected Hub port from total cost point of view, operation cost, port charge, feeder cost, etc.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.253-260
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• 2004

In these days, 8000TEU container ship service launches in shipping service at latest based on the economy of scale, unit cast related with ship operation on ocean decreases in proportion to increase of ship scale and mega ship over 10,000TEU is on planning. This paper is analyzed the economic efficiency for reduction qf calling port in the operation cost, port chnrge, feeder cost, etc by an empirical analysis.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.9
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• pp.1391-1397
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• 2015

Recently, various researches are conducted in the application of regenerative energy produced during the operation of an electric locomotive. Regenerative energy is produced by a generator in the brake procedure. The generator is operated by kinetic energy of an electric railroad using an electric motor. The process of producing regenerative energy varies with the current type of a railroad and its running condition. The quality of electric power can be improved and electric energy can be utilized effectively, especially in the use of an energy storage system (ESS). Thus, it is necessary to apply ESS into AC section and high speed railway. This study analyses the composition of the regenerative ESS equipment installed in Yong-Jeong sectioning post, operational principle, charge and discharge algorithm and energy efficiency. The analysis shows that CO2 emissions can be reduced about 0.5 ton per a day. In addition, ESS helps saving the energy and the compensation of the voltage drop caused by the operation of high speed train when it is installed at the end of the feeder section. The number of high speed train will be increased continuously related to the electrification rate. Therefore, applying the ESS to high speed railway is expected to solve the instability of the feeder voltage and the equipment capacity problem caused by the high speed trains.

• Journal of Navigation and Port Research
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• v.30 no.1 s.107
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• pp.53-59
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• 2006

Recently, 8,000TEU class containerships has started operating the shipping service and the mega-containership of over 10,000TEU is on planning. A unit cost in relation to shipping service is decreased by the bigger ship based on the economy of scale. Most of the previous studies have been performed and focused on the total operation cost from mega port to mega port. However, the purpose of this paper is to estimate economic efficiency of selected hub ports from point of view of total cost such as service cost(or operation cost), port charge and feeder cost, etc. First, the service-network of mega containerships is based on data of a domestic shipping company operated main line and economic analysis of individual scenarios on the cost and traffic when 10,000TEU mega containerships offer the services. The three scenarios presented in this paper set up the hub ports which are the port of Busan, Shanghai and Yokohama The results show that port of Busan is economically the most efficient one among others.

• Journal of Navigation and Port Research
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• v.28 no.8
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• pp.709-714
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• 2004

This paper first tries to analyze total sea transport costs for the transshipment in Busan Port in comparison with direct transport to 4 Chinese Ports, Dalian, Tinajin, Qingdao and Shanghai, based on vessel operation scenarios. The results found that the transshipment in Busan port for the 4 Chinese ports are more expensive than the direct calling to the 4 ports, which implies that Busan port needs to make compensation as an incentive to the carriers providing transshipment service to it in order to keep their royalty. For the compensation, it suggested a method of calculating the Container Terminal Facilities Leasing Fee to levy additional revenue by port authority.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.127-132
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• 2004

Most q the domestic container terminals are inferior to throughput q container. The reason why they have the difference between the handling capacity q planed quay and its real. By putting into quay handling equipment, the productivity of quay can be improved, waiting rate q the ship can be lowed. This paper suggests more resonable terminal construction, throughout comparing with previous construction way, improved handling capacity and the economical efficiency of equipment costs, labor costs, construction costs, operation costs on change of terminal size by adding the equipment.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.4
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• pp.247-256
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• 2008

Regenerative energy generated by regenerative braking of DC traction can cause the system malfunction or damage to the rectifier, or malfunction of the power conversion device in power supply system by DC Line voltage rise in feeder line. Regenerative energy storage system using super capacitor is one of the ways to stabilize DC line voltage. In this paper, energy storage system of DC traction system using super-capacitor bank is implemented and using the field measurement data of the station N and the station S on the Line 2, the operation characteristics of line voltage caused by regenerative energy of electric trains are verified. Also, charge/discharge characteristics of super capacitor are verified as well. Thus, we can verify the operation characteristics of super-capacitor bank for regenerative energy storage system installed in DC Traction. And if we can use field measurement data of DC line voltage, we have obtained cost reduction. The stabilization of the system will be improved by measuring the operation characteristics of regenerative energy storage system in certain section operated by DC traction and predicting the capacity and lifetime of super-capacitor.