• 대한전기학회논문지
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• 제35권7호
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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.

• 한국측량학회지
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• 제20권1호
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• pp.33-38
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• 2002

본 연구는 GPS측량에 의한 실용측지점 활용의 타당성에 관한 논문으로 위성측량의 효율적인 자료처리를 위해 WGS-84 data를 우리나라 경위도 좌표계로 변환시킨 자료와 현재 사용하고 있는 광주광역시 일원의 기존 삼각점 및 도근점 10개를 선택하여 GPS성과와 기존성과를 비교 분석하여 신뢰성을 검증하고자 하였다. GPS위성을 통하여 기존 삼각점 및 도근점을 측량한 결과 종래 측량방법보다 신속하고, 오차의 균일성도 확보할 수 있으며, 좌표변환이 전산처리 됨으로 장래의 측지 및 지적측량에 효과적인 방법임을 알 수 있었다. 그리고 GPS측량의 성과와 기존 측지측량 및 지적측량성과를 일치시키기 위해서는 우리나라 전역에 대한 측량 당시의 좌표결정방법을 집중적으로 연구하여 GPS 관측 시 각 권역별 성과와 일치된 좌표변환계수를 계산하여 장래 GPS측량에 효과적으로 실용화 시켜야 함을 알 수 있었다.

• 대한전기학회논문지:전력기술부문A
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• 제49권6호
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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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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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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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• 통권20호
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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.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 추계학술대회 논문집
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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

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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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.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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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.

• 한국환경과학회지
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• 제23권4호
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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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• 제어로봇시스템학회 2005년도 ICCAS
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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.