• Journal of the Korea Society of Computer and Information
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• v.21 no.3
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• pp.9-15
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• 2016

In this paper, DC-PLC typed one-wire controller was designed and manufactured especially for In-vehicle safe devices. One-wire by DC-PLC scheme is to be used as a power supply and ground to process the sensor data and to operate the vehicle actuators. To avoid complicate wires, we use the conventional wires without installing extra communication lines. The data collected from the sensors are transmitted to the main controller, processed by programming, and run the actuators corresponding to the commands sending to vehicle control board. The proposed method shows that only One-wire without requiring several wires make In-vehicle control devices simple and reduce the damage due to the loss of the wiring.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.12
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• pp.2135-2142
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• 2010

This paper studies the validity about a joint operation of neutral wire and overhead grounding wire in combined distribution systems. The overhead grounding wire and neutral wire are currently installed separately and grounded by common. However there is no any ineffectiveness or electrical problem in case of the proposed system, such system can be operated at real distribution system. Therefore this paper describes the suitability of a joint operation through lightning surge analysis on combined distribution systems. Lightning surge analysis is carried out by EMTP/ATPDraw to obtain the overvoltage of overhead line and underground cable in various conditions such as locations and current types of lightning stroke. Overvoltage gained by the analysis show that the insulation strength of the joint operation case is not stable compare with the current operation case.

• Wind and Structures
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• v.22 no.3
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• pp.369-391
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• 2016

Electricity is transmitted by transmission lines from the source of production to the distribution system and then to the end users. Failure of a transmission line can lead to devastating economic losses and to negative social consequences resulting from the interruption of electricity. A comprehensive in-house numerical model that combines the data of computational fluid dynamic simulations of tornado wind fields with three dimensional nonlinear structural analysis modelling of the transmission lines (conductors and ground-wire) is used in the current study. Many codes of practice recommend neglecting the tornado forces acting on the conductors and ground-wires because of the complexity in predicting the conductors' response to such loads. As such, real transmission line systems are numerically simulated and then analyzed with and without the inclusion of the lines to assess the effect of tornado loads acting on conductors on the overall response of transmission towers. In addition, the behaviour of the conductors under the most critical tornado configuration is described. The sensitivity of the lines' behaviour to the magnitude of tornado loading, the level of initial sag, the insulator's length, and lines self-weight is investigated. Based on the current study results, a recommendation is made to consider conductors and ground-wires in the analysis and design of transmission towers under the effect of tornado wind loads.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.12
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• pp.1818-1823
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• 2015

In this paper, we analyzed the optimal configuration of protection wire that have been installed in the electric railway power supply system. Protection wires are to suppress the ground potential rise when the short circuit fault between contact wire-rail(C-F), and protect the electronics equipments(signalling and communication) that are facility the wayside. The role of protection wires must be feed back quickly the fault current to the substation when a short circuit fault occurs. In this paper, we proposed that only one line to install the protection wire. Comparing how to newly proposed and existing system, most of the performance is similar. The reason is that most of the current flowing in the protection wire near the location where the fault occurred. There is no problem even if in one line for human safe and the low impedance of the return circuit in dimension to ensure the safety of the facility during the fault. To ensure safety during an fault occurs, it is sufficient even by one line. But, In the protection wire of facilities planning it is necessary to design taking into account the potential utility.

• Proceedings of the KIEE Conference
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• 2005.07e
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• pp.127-129
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• 2005

OPGW(Optical Ground Wire) whose demand is increasing worldwide have composite function as optical communication and grounding for preventing transmission line from lightning. While continuous efforts have been made to increase the transmission capacity and speed, the working method to replace the existing ground wire with OPGW under live-line condition is coming to force newly as installation aspects. Particularly, this requirement became more serious in developing country that the electric power supply is not sufficient and power outage is impossible for supply and dead of electric power LS cable Ltd. has developed the new installation method in full live-line condition to solve the confronted problem and to meet the market demand. In this paper, Electric Problems in live-line installation is considered to predict dry-band arcing. This can be used by Makers to predict dry-band arcing in insulating ropes installed on earth wire of power transmission system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.05b
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• pp.213-217
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• 2009

Underground structures are built into concrete like a architecture and public works. Concrete has watertightness as such, But buildings are leaking from the cracks. Recently, construction method do a lot of close construction in the downtown area. So architects are using the method for the outer layer of a two-layer wall to save spaces. They have been using Top-down method and waterproof agent method and others to outer layer of a two-layer wall method. But, There are many leakage in underground structure from lack on requirements performance of materials. Therefore, I hope to test the outside Waterproof Method of Ground using Wire-mesh and Non-hardening Viscosity Waterproof. In addition to, I wish to apply as outside waterproof method for the section for the outer layer of a two-layer wall in underground structure.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.4
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• pp.329-334
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• 2021

Korean Air has set the goal of the first stage of the development of unmanned helicopters to perform in hovering flight by remote control. In order to achieve the development goal, Korean Air carried out system integration, ground test, and safety wire test in sequence after carrying out programmed depot maintenance and aircraft modification of manned aircraft, and verified the controllability and flight safety of the unmanned helicopter system step by step. In particular, it was confirmed that the safety wire test technique used in the final stage of verification was an effective method to verify flight safety and controllability for a fully unmanned helicopter system.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.165-167
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• 2000

This paper presents the influence of the lightning overvoltage and the shielding effects of overhead grounding wire on the DC railway system. Modeling of Railway system is established in ATPDraw to perform simulation. The result of simulation reveals that the shielding effects of overhead grounding wire has over 90% than the case which has not it. Therefore it is evaluated that overhead grounding wire should be installed in the DC railway line.

• Journal of the Korean Society of Industry Convergence
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• v.17 no.2
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• pp.61-68
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• 2014

Constructing structures is the basic process requiring establishment of grounds. However, cracks due to sinking and distorting ground influence directly on the safety of structural health. Vibrating wire sensor measures the crack of structure by detecting the differences of wire tensions in analogue manner. In the previous production process, the tension is adjusted manually measuring the frequency of vibrating wire. Therefore, the accuracy of a sensor was depends on the skill level of labor. In this study, the automatic tension control and fixing devise is developed to enhance both accuracy and productivity. To evaluate the performance of the vibrating wire sensor, the nonlinearity of sensor is measured. The automatic tension control and fixing devise enhances the nonlinearity of the sensor from 0.398 to 0.056%. Therefore, the accuracy of the newly proposed method is successful.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2560-2565
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• 2003

The paper presented here covers the work associated with the flight control law design, ground based and in flight simulation and handling qualities assessment of the Fly-by-Wire type Aircraft (FBWA). The control law was designed for the most unstable aircraft configuration flight regime for the target aircraft (FBWA). The ground based simulation including math-model, real-time pilot-in-the-loop and iron bird simulation were used for validation of the control law before the experimental in-flight simulation on the IFS (In.Flight-Simulator) aircraft. The flight tests results showed that Level 1 handling qualities for the most unstable flight regime were achieved.