• ETRI Journal
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• v.30 no.2
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• pp.249-254
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• 2008

In this paper, we demonstrate an electrically band-limited carrier-suppressed return-to-zero (EB-CSRZ) signal generator operating up to a 10 Gbps data rate comprising a single-stage Mach-Zehnder modulator and a wideband signal mixer. The wideband signal mixer comprises inverter stages, a mixing stage, and a gain amplifier. It is implemented by using a 0.13 ${\mu}m$ CMOS technology. Its transmission response shows a frequency range from DC to 6.4 GHz, and the isolation response between data and clock signals is about 21 dB at 6.4 GHz. Experimental results show optical spectral narrowing due to incorporating an electrical band-limiting filter and some waveform distortion due to bandwidth limitation by the filter. At 10 Gbps transmission, the chromatic dispersion tolerance of the EB-CSRZ signal is better than that of NRZ-modulated signal in single-mode fiber.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.854-858
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• 1987

This paper considers impulsive noise which produce burst error in high speed(approx.160Kbps) data transmission like ISDN(Integrated Servise Digital Network) using PSTN(Public Switching Telephone Network). To begin with, we obtains the transfer function of subscriber line to calculate the variation of bandwidth when the gain of receiver is fixed and channel capacity of non-gaussian channel in upper-and lower bound, and evaluates the transmission capability. In this paper compares channel capacity bounds which obtains when probability density function of impulsive noise is Laplacian distribution function with impulsive noise generated by waveform synthesier.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.3
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• pp.464-473
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• 2000

The method is presented which predicts voltage waveforms at each nodes inter-connected arbitrarily on the coupled transmission lines by extracting the node connection condition to be included in the modal telegrapher's equation, hence analyzing the mechanism of waveform propagation on transmission lines. It is shown that it is also possible to analyze efficiently the coupled nonuniform lines. And then the nonuniformity of coupled lines is demonstrated for suppressing the crosstalk spikes using the one-dimensional inverse-scattering control theory. The predicted waveforms by presented method are analyzed and verified by comparison with those by the generalized S-parameter technique.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.4
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• pp.107-117
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• 1996

The shift feeling, a driver experiences during gear shifting, is a major factor in manual transmission quality. Recently, the shift feeling has becoming more severe every year in proportion to the higher torque and revolution speed of today's automotive engine. In this paper, first, the diagram of a relation between cone angle, sleeve chamfer angle, and friction coefficient of ring is investigated for easy design of Synchromesh system. And then, methodology to solve the shift problems such as clashing noise and rough shift, ect. by analyzing the synchronization procedure in sequence and by investigating the shift waveform if presented.

• Journal of the Semiconductor & Display Technology
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• v.3 no.1
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• pp.31-34
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• 2004

We develop Mueller-matrix spectroscopic ellipsometry based on dual compensator configuration. This technique is very powerful for measuring surface anisotropy in nano-scale, especially when materials show depolarization. Dual-rotating compensator configuration is adopted with the rotational ratio of 5:3 originally developed by Collins et al[1]. The instrument can provide 250-point spectra over the wavelength range from 230 nm to 820 nm in one irradiance waveform with minimum acquisition time of Tc=10 s. In this work, the results obtained in transmission modes are presented for the initial attempt. We present calibration procedures to diagnose the system from the utilized data collected in transmission mode without sample. We expect that the instrument will have important applications in thin films and surfaces that have anisotropy and inhomogeneity.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.233-236
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• 2000

A portable equipment that measures a current and voltage waveform of power transmission lines is pro-posed. In the equipment, the current and voltage, respectively, are detected by a loop coil and a capacitor clamped around the power lines. The detected data is transmitted by an FM wave to the receiver on the ground station. Since the receiver is isolated from the power lines, we do not require high potential insulators for the measurement of current and voltage. The proposed equipment is therefore, small-sized, light, and low in the cost of production. Experimental results presented here show that the equipment can monitor the current flowing in single wire over a ground plane and the potential of the wire.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2003.12a
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• pp.12-17
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• 2003

We develop Mueller-matrix spectroscopic ellipsometry based on dual compensator configuration. This technique is very powerful for measuring surface anisotropy in nano-scale, especially when materials show depolarization. Dual-rotating compensator configuration is adopted with the rotational ratio of 5:3 originally developed by Collins et al [1]. The instrument can provide 250-point spectra over the wavelength range from 230 nm to 820 nm in one irradiance waveform with minimum acquisition time of $Tc{\approx}10 s$. In this work, the results obtained in transmission modes are presented for the initial attempt. We present calibration procedures to diagnose the system from the utilize data collected in transmission mode without sample. We expect that the instrument will have important applications in thin films and surfaces that have anisotropy and inhomogeneity.

• Journal of IKEEE
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• v.21 no.3
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• pp.256-259
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• 2017

SENT (single edge nibble transmission) is a serial communication protocol between automotive sensors and ECU (electronic control unit). SENT exploits digital waveform, so it has a simple and cheap architecture without transceiver circuits. Usually it is exploited as an embedded communication interface in the sensors. In this paper, a SENT interface was designed in Verilog HDL, fully complying with SAE J2716. It was implemented in FPGA, and verified on a test board. When it was synthesized, the gate count is about 2,500 gates in 0.18um technology.

• Journal of Electrical Engineering and Technology
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• v.1 no.3
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• pp.279-286
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• 2006

A method for estimating the instantaneous phasor of a fault current signal is proposed for high-speed distance protection that is immune to a DC-offset. The method uses a modified notch filter in order to eliminate the power frequency component from the fault current signal. Since the output of the modified notch filter is the delayed DC-offset, delay compensation results in the same waveform as the original DC-offset. Subtracting the obtained DC-offset from the fault current signal yields a sinusoidal waveform, which becomes the real part of the instantaneous phasor. The imaginary part of the instantaneous phasor is based on the first difference of the fault current signal. Since a DC-offset also appears in the first difference, the DC-offset is removed trom the first difference using the results of the delay compensation. The performance of the proposed method was evaluated for a-phase to ground faults on a 345kV 100km overhead transmission line. The Electromagnetic Transient Program was utilized to generate fault current signals for different fault locations and fault inception angles. The performance evaluation showed that the proposed method can estimate the instantaneous phasor of a fault current signal with high speed and high accuracy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4740-4744
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• 2012

The purpose of this paper was to make a LED light control module using Zigbee. The module was made so that brightness of the LED light changes according to the ambient brightness. A 8-bit microcontroller was used to implement the module to enable LED dimming and wireless light intensity measurement. Using the proposed method, power consumption can be improved by up to 48% on average, with 3.4-0.4W changes in power. The measured ambient light intensity values are converted from analog to digital and outputted as a PWM waveform. According to the output waveform and changes in the current outputted from the LED driver, the brightness of the LED light is controlled. Also, Zigbee with close-range wireless communication capabilities was used to enable wireless transmission of light intensity measurements.