• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.7
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• pp.285-295
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• 1986

This study is to investigate the stability of expanded new generator plant depending on the capacity of existing system. We examined the transmitting power limit to the existing system as its capacity increase for the various system configuration with fixed location of plants and substations. The results show that the stability has decreasing tendency when the existing source capacity increase. Thus it can be concluded that new generator has little stability problem when it connected to small system, whereas large existing system capacity gives remarkable difficulty in adopting new generator.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.1
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• pp.33-38
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• 2002

The object of this study is to verify the feasibility in the application of the GPS system data to the existing geodetic and cadastral survey system. WGS-84 data, which were converted into domestic geometric coordinate system, were compared with those of the existing triangular coordinate system in Gwangju area. The significant results in this study are summarized below ; GPS system is more speedy and accurate than the existing triangular coordinate system in the survey of points in triangular coordinate or on the map. And the error in the GPS system was more uniform than that of the existing triangular coordinate system. GPS system is more effective than the existing triangular coordinate system in the future geodetic and cadastral survey because GPS data can be processed by the computer. It is necessary to calculate the conversion coefficients to apply GPS data practically to the existing geodetic and cadastral survey system. It can be achieved by the individual investigation on how the existing data in the domestic coordinate system were determined.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.6
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• pp.280-288
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• 2000

Recently, there has been growing interest in utilizing cogeneration(COGN) systems with a high-energy efficiency due to the increasing energy consumption and the lacking of energy resource. But an insertion of COGN system to existing power distribution system can cause several problems such as voltage variations, harmonics, protective coordination, increasing fault current etc, because of reverse power of COGN, especially in protective coordination. A study on a proper coordination with existing one is being required. The existing power distribution system is operated with radial type by one source and protection system is composed based on unidirectional power source. But an Insertion of COGN system to power distribution system change existing unidirectional power source system to bidirectional power source. Therefore, investigation to cover whole field of power distribution system must be accomplished such as changing of protection devices rating by increasing fault current, reevaluation of protective coordination. In this paper, simulation using PSCAD/EMTDC was accomplished to analyze effect of COGIN on distribution fault current. Also, the existing protection system of 22.9[kV] power distribution system and customers protection system to protect of COGIN was analyzed and the study on protective coordination between of two protection system accomplished.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.41-46
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• 1990

In the existing robot programming methods, off-line method becames important role of programming because of improvement of hardware and software of PC. The purpose of this study is to develop practical robot programming system for polishing task using PC. In the first place, we have investigated the existing robot programming systems, and derived the requirement of this programming system from the existing systems. And we have decided the structure of this system. After that, we have developed this system. Using Windows software, this programming system has man/machine interface function. So users can use easily and quickly.

• 한국기계연구소 소보
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• s.20
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• pp.33-39
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• 1990

In the existing robot programming methods, off-line method because important role of programming because of improvement of hardware and softeare of PC. The purpose of this study is to develop practical robot programming system for polishing task using PC. In the first place, we have investigated the existing robot programming systems, and derived the requirement of this programming system from the existing systems. And we have decied the structure of this system. After that, we have developed this system. Using Windows software, this programming system has man/machine interface function. Therefore users can use easily and quickly.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.267-272
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• 1999

The auxiliary power supply system fur passenger service of railway car has been developed from MA(Motor-Alternator) to CVCF Inverter (Static Inverter). Generally, a customer wants to apply tile new control method and device for auxiliary power supply of railcar However, if the auxiliary power supply is supplied to extended existing line, the maintenance cost of the old system is less expensive than new developed system, so, the customer specifies that the auxiliary power supply has compatibility with existing one completely. At that time, the hardware is nearly same as existing system except small changes of accessories for better performance. This paper describes the flicker control using feed-forward method of auxiliary power supply system for new 50 electric railcars, which are delivered to Korean National Railroad (KNR) Kwa-chon Line. The existing power supply system has damping resistor box to stabilize the DC input (1.5 ㎸). At this time, for better system efficiency the new system has not include resistor box but new control method including feed-forward control is applied. This control algorithm realizes the better stabilization of input power compared to the result of the existing system, which includes resistor box

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.30-33
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• 2004

This paper suggested that the technical specification of tilting train EMU for speed up on existing lines. High speed strategy of existing lines are the modification of railway system which are made on cant, lengths of transition curves, the catenary system and train system. Tilting technology is more useful a strategy for speed increases on existing lines with low investment needed. We performed a feasibility study which is considered out real track conditions and designed propulsion and braking system of tilting EMU system.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1550-1555
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• 2011

This paper presents the system interface standard that are associated with additional devices like sensor nodes as well as fire monitoring panel, panic button and emergency call in city railroad environment. Existing fire monitoring panel, panic button and emergency call system is responsible for fire detection and alarm, emergency alarm and communication with the manager. Recently, researches that are associated with NVR-based intelligent integrated surveillance systems and existing alarm system are activated but most of the system is dedicated to it existing. In order to expand devices that is supported other monitoring function, separate device configuration or modification of integrated surveillance system are inevitable. In this study, interface standard between standard controller, integrated command center and each device that facilitate additional expansion of integrated surveillance system and avoid the extra cost is presented.

• Journal of Environmental Science International
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• v.23 no.4
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• pp.737-742
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• 2014

This study aimed for evaluating the applicability of the two stage dual media filtration system in field water treatment plant. The field plant of two stage and dual media filtration system was operated for 2 months. Average iron concentrations of the settled water, existing filtered water and second stage filtered water was 0.041 mg/L, 0.007 mg/L and 0.005 mg/L, respectively. Removal efficiency of iron concentration in the second stage is appropriately 35% more than in existing filtered water. Also removal efficiency of residual chlorine in the dual media filtration system is relatively 42.3% more than in existing filtered water due to adsorption of activated carbon, but the removal of ammonia nitrogen by adsorption is insufficient. Average concentrations of THM and chloroform in the settled water are 0.033 mg/L, 0.026 mg/L, respectively and in existing filtered water are 0.023 mg/L and 0.023 mg/L. Average concentrations of THM and chloroform in the dual media filtration system are 0.008 mg/L and 0.013 mg/L. Therefore removal efficiency of THM concentration in second stage is more than 66.4% in existing filtrated water. Also removal efficiency of chloroform in the dual media filtration system is more than 50.0% in existing filtered water because of the adsorption of activated carbon. In this case backwashing period in dual stage system is 4~5 days, but in existing filtration system is 1~2 days.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1304-1308
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• 2005

This paper presents the case that the existing analog control systems were retrofitted with digital DCS(Distributed Control System)s for boiler unit in thermal power plant. Replacement of existing worn-out or obsolete analog control systems has been considered. Replacement of existing analog control systems with another analog control systems has lots of difficulties in maintaining the systems due to being out of stock. Due to those difficulties, existing analog control systems have been retrofitted with digital DCSs in many industrial sites. KEPRI(Korea Electric Power Research Institute) accomplished the project that retrofitted analog control systems with the developed DCSs for boiler unit in middle-scale coal-fired thermal power plant. The benefits of an upgrade to digital control include a increase of reliability due to system redundancy, ease of modifying the control logic and the parameters of function block, ease of maintenance due to available spare parts, improvement of information display, ease of modifying MMI(Man Machine Interface) displays, a increase in system availability, and improvement of control performance. This paper describes how to use the parameters of existing analog controllers, the implementation of digital PID controller, control system configuration for boiler unit in thermal power plant, some boiler control loops, control result during commissioning, and the comparison of boiler characteristic test data after retrofitting with the existing test data.