• 동굴
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• 제85호
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• pp.15-17
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• 2008

This paper is attempted to review a cave restoration and preservation plan against environmental destruction and pollution as a preliminary survey for preservation of cave environment. Consequently, it's important to throw an indirect light rather than direct light on cave formations, keeping distance of 2m at least. The already existing moss should be removed using wet cloth or sponge as soon as possible. If it's washed off, be careful not to splash it or water on nearby subjects. Based on an automatic switch-off system, light will automatically turn off when no one is left in the cave. It's also recommended to dualize the cave passage and partially close the cave by taking turns to give a time to recover.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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• pp.76-78
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• 2000

The previous MCC's have the demerits of high cost and much manhour for rework because they are impossible for the standardization of products and have many manual connections. The customers require the products which can operate in connection with SCADA system by digitalizing the functions of the current MCC's and are systematized with capability of remote control. To solve these disadvantages and requirements, we developed the Electronic Motor Control System according to starting type for applying to fields based on this. This system has the various functions such as protection, measurement, and communication. Using these functions, it can monitor motor status through communication with the upper system and define the circuit for lower connection cost according to starting type and shorter manufacture period by program. The development of this product results in establishment of competitive structure with domestic competition and perfect automatic monitoring through linkage with SCADA system. In addition, it provides the comparable dominancy of receiving on orders in switch gear and adaptability to change of MCC market in Japan and Europe.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1422-1424
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• 1999

This Paper Presents a efficient algorithm for loss reduction of distribution system by automatic sectionalizing switch operation in distribution systems of radial type. To apply tabu search to reconfiguration of distribution system, in this Paper we Propose the several move methods and efficient reconfiguration procedure. We also discuss the tabu search techniques of diversifying the search of solution space as well as the simple tabu search. The experimental results show that the proposed tabu search techniques have the ability to search a good solution.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1428-1430
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• 1999

The New Distribution Automation System(NDAS) was composed of several equipments, computer system, communication system, feeder remote unit, switches and so on. In this paper, we introduce the conception of hardware and software design about Central Control System, the communication method and protocol in Feeder Remote Unit, the Automatic Switch, the operating software, consideration factors in the feeder automation(FA) and the system configuration of NDAS in power distribution test center.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.810-814
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• 2001

power transfer breaker is a device used to transfer the load from the electricity power line to the emergency generators. In case of overload, it also functions as a circuit breaker. In this work, a new mechanism for the device is suggested. Among the various design challenges, optimization of the trigger mechanism is identified as of central importance. Optimal design decisions are made with the use of Taguchi method.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.222-227
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• 2000

"Side scan sonar" using acoustic signal has been developed to survey cable laying, sunken bodie\ulcorner bottom and so on. It use the acoustic signals, which are emitted from two transducer arrays, to get gemetri\ulcorner target area. This system consists of transceiver board, towed body, and deck unit. The transceiver board, w\ulcorner watertight canister of the towed body, controls the transmitting and receiving of 400kHz acoustic signals from \ulcorner After receiving the scattered signals, it processes the filtering, AGF(Automatic Gain Control), TVG(Time Heterodyne. The deck unit is composed of the signal processing part, A/D converter, power supplier, and real\ulcorner And the towed body has been designed to satisfy the optimal hydrodynamic behavior during towing. The de\ulcorner theory of transceiving part and some results from field-experiments will be introduced here.

• Journal of electromagnetic engineering and science
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• 제1권2호
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• pp.131-138
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• 2001

The DTV (Digital TV) tuner for an 8-VSB (Vestigial Side-Band) modulation was developed to meet the requirements of the ATSC (Advanced Television Systems Committee). The double frequency conversion and the active tracking filter in the front-end were used to cancel interferences between adjacent channels and multi-channels by suppressing the IF beat and the Image frequency. However, It was impossible to get frequency mapping between the tracking filter and the first VCO (Voltage Controlled Oscillator) in the existing DTV tuner structure which differs from the NTSC (National Television Systems Committee) tuner. This paper, therefore, suggests an assailable structure and a new method for the automatic frequency selection by mapping the frequency characteristics over the tracking voltage and the combined HW which is composed of a Micro-controller, an EEPROM (Electrically Erasable Programmable Read Only Memory), a DAC (Digital-to-Analog Converter), an OP amplifier, and a switch driver.

• KIEAE Journal
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• 제12권1호
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• pp.119-125
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• 2012

The objective of this study is to evaluate the electric lighting energy consumption carried out by Daysim program. A comparison between the measurement and simulated exterior global horizontal illuminance shows differences about 10% and it is very similar to the measurement. The interior illuminance simulated by Daysim are 18.9% lower than the measurement and simulated lighting energy consumption is 10% lower than the measurement. Corrected annual lighting energy simulation results show that the best case is the combination of occupancy switch-off and dimming system with automatic controlled blinds (E-3). In case of no blinds, it occasionally derives the minimum lighting energy consumption but it causes the glare, so we need to be careful for choosing the control strategy. For the overcast sky, the lighting energy consumption is not changed significantly by control strategy while the lighting energy in the clear sky is changed noticeably. So we must know the right strategy for each case to control the electric lights and blinds.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.325-329
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• 2002

This paper is intended as an investigation of the interface between Neutral section insulators and pantograph interface. Neutral section insulators are installed at the boundary between AC catenary system and DC catenary system, which should provide electrical insolation between two different catenary systems and pass the trains without interruption. As the number of the pantographs installed on the train increased, which is necessary for the VVVF inverter drive trains introduced in recent years, there occurs an serious aspects of the interaction between pantographs and Neutral section insulators. These effects hinder the automatic switch operation of MCB(Main Circuit Breaker) after passing through the section insulators, and lead to the extra-ordinary wear of FRP insulator material of section insulators. Countermeasures in terms of the interface between the Neutral secton insulators and electric collection system of train are provided too.

• 한국통신학회논문지
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• 제23권6호
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• pp.1503-1513
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• 1998

This paper is related to a performance analysis of B-NT system, which is essential compositional equipment of B-ISDN access network. A simulator enabling performance analysis according to the change of network configuration topology and the change of user traffic is developed in this study. The developed B-NT, system simulator consists of graphic user interface module, simulation program automatic generator module, and B-NT system model library module. As examples of the results of performance analysis using the simulator, end-to-end user cell transmission delay time, queueing delay time in each system, and cell loss rate in the head node switch are presented. The simulator developed in this paper can be utilized in determining the network topology of B-NT system.