• ETRI Journal
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• v.37 no.1
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• pp.128-137
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• 2015

In this work, a fishbone-type transmission line employing a comb-type ground plane (FTLCGP) was fabricated on polyethersulfone (PES) substrate, and its RF characteristics were thoroughly investigated. According to the results, it was found that the FTLCGP on PES showed periodic capacitance values much higher than other types of transmission lines due to a coupling capacitance between the signal line and ground, which resulted in a reduction of wavelength and line width. Using the theoretical analysis, we also extracted the bandwidth characteristic of the FTLCGP on PES. According to the result, the FTLCGP structure showed a cut-off frequency of 280 GHz.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.2215-2222
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• 2010

Advanced EMU have been enhanced in terms of safe transport and maintainability. It is a new urban railway technology that enables an operation institution to cut repair and maintenance costs and customers to use convenient service at lower costs based on IT technology. If a development vehicle of Advanced EMU is completed, it will be used to test the entire advanced EMU system through sufficient performance check and reliability check prior to operation in commercial line. It will also verify efficiency, safety, punctuality and energy efficiency of transport. Accordingly, it is necessary to figure how to repair and maintain vehicles to enhance safety of Advanced EMU system in cooperation with operation during the period of comprehensive evaluation on the operation of a development vehicle in a test line. In this paper, we investigated the maintenance program of Advanced EMU on test operation in Dabul line. The test condition and operation environment of Advanced EMU in Daebul line was analyzed.

• ETRI Journal
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• v.33 no.6
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• pp.985-988
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• 2011

A novel application of a dual-transmission line is proposed to design a lowpass filter (LPF). The proposed structure uses only transmission line elements to produce an equiripple LPF response with sharp roll-off. Design equations are derived using a lossless transmission line model. Controlling the electrical lengths, three transmission-zeros are realized in the stopband to obtain a sharp roll-off rate and wide stopband bandwidth. A single unit microstrip LPF with a 3-dB cut-off frequency at 1.0 GHz having a roll-off of 135 dB/GHz along with a stopband bandwidth of 69.5% is designed for validation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.625-627
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• 2008

In this paper, a vertical via transition using a coaxial line is presented for LTCC SMT package applications. A part of outer conductor is cut off due to overlap between a CPW on PCB and transition. For reduction of radiation and return path, a cap is designed on the top layer. The measured S11 and S21 are -14 and 0.9dB, respectively at 15GHz.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.262-269
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• 1998

In case the fault occurs in AC power supply network, protective relaying system must selectively detect line-to-line/ground fault and immediately cut off the power flow into the fault location for guaranteeing the safety of people, electric vehicle and ground installation etc. It is the most important point in power system operation to minimize the fault duration by rapid trip scheme and accurate estimation of the fault location. In this paper, we analyze the load characteristics of each vehicle, perform the fault analysis of AC power supply network using AT current-ratio method. The result shows its usefulness.

• Transactions of Materials Processing
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• v.15 no.4 s.85
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• pp.311-318
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• 2006

One of the most important quality problems in flat plate leveled from hot rolled coils in cut-to-Iength lines is bowing and cambering when they are cut in small width parts. It is verified analytically and experimentally that residual stress remained in plate is th ε source of the problem. In order to produce low residual stress flat plate from hot rolled coils, the proper conditions of leveling are studied and two things are implemented. One is proper plastic deformation area ratio to reduce residual stress within customer requirement by applying suitable plastic deformation and maintain leveling load within structural strength limit of leveler. The other is maintaining uniform plastic deformation along the width of the plate during leveling. Customer requirement for residual stress is met by applying above 70% of plastic deformation area ratio and uniform deformation along width of coil by adjusting back up rolls according to deformation analysis of work roll and back up roll assembly and leveling tests.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.2
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• pp.95-101
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• 2014

This paper explains effective tracking method for a vehicle cutting in a line on the road automatically. The method employs KLT based on optical flow using play-back image sequence. Main contribution of this paper is play-back image sequence that is in order image frames for rewind direction from a reference point in time. The moment when recognizing camera can read a license plate very well can usually be the reference point in time. The biggest images of object traced can usually be obtained at this moment also. When optic flow is applied, the bigger image of the object traced can be obtained, the more feature points can be obtained. More many feature points bring good result of tracking object. After the recognizing cameras read a license plate on the vehicle suspected of cut-in-line violation, and then the system extracts the play-back image sequence from the tracking cameras for watching wide range. This paper compares using play-back image sequence as normal method for tracking to using play-forward image sequence as suggested method on the results of the experiment and also shows the suggested algorithm has a good performance that can be applied to the unmanned system for watching cut-in-line violation.

• International Journal of Korean Welding Society
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• v.3 no.1
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• pp.2-7
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• 2003

Laser welding application for car body manufacturing has many advantages in the stiffness and the lightness of vehicle, the productivity of assembly line, and the degree of freedom in design. This presentation will express the innovation of car body manufacturing including parameter optimization, process modeling, and system integration. In this application the investment for systems was cut down dramatically by real time switching over the laser path between two welding stations. Points of technical discussion are as follows; optimization of parameters such as laser power, robot speed and trajectory, compact and useful design of jig & fixture to assure welding quality for 3 sheet-layer zinc-coated steel, system integration between 4㎾ Nd:YAG laser device and the other systems, on-line real time welding quality monitoring system, perfect safety standards for high power laser, minimization of consumption costs such as arc lamp, protective glass for optic, etc. This application was successfully launched mass production line in 2001. The laser-welded line of side panel consists of 122 stitches totally. And the length is about 2.4m.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1091-1093
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• 1999

This paper discusses the surveying of a power transmission line using Real Time Kinematic(RTK) GPS technology. The use of RTK provides users with an accurate position at the moment in time. Application result of a 765kV transmission line surveying proved to be more accurate and efficient than using a traditional EDM (Electro-magnetic distance measurement) method. More, decrease in numbers of trees cut down which is a major cause of public discontents was achieved. Improvements in doing a surveying of a power transmission line using GPS is expected in the future.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.88.5-88
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• 2002

A new floating power supply for the current measurement system of a high voltage power line is developed. It is confirmed that, the current measurement system can stably transfer the signal of the power line current about 50 - 300 A by using the proposed power supply. The excellent characteristics are obtained by the steady-state and transient experiments of the proposed circuit. $\textbullet$ The right figure shows the external view of the trial measurement system for 6.6 kV. In order to see the inside, 120 degrees of the insulator is cut. The toroidal coil for the power supply and the Rogowskii coil for the current sensor are both divided into two and fixed on the power line as...$\textbullet$ The proposed circuit can supply +5V and -5V voltages without using a solar cell and/or a battery.