• Journal of Sensor Science and Technology
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• v.21 no.1
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• pp.75-81
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• 2012

Optimizing the tapping time of a blast furnace is important to a stable operation and life extension. To optimize the tapping time of the blast furnace, the location of Hearth Liquid Level should be recognized. There are several ways to measure the hearth liquid level in the blast furnace, such as Electromotive Force(EMF) measurement, pressure measurement by putting in nitrogen probe and manometry with strain gauge. In this paper, it will be discussed using strain gauge among the three methods. Conventional strain gauge must be revised periodically. Since, internal pressure, temperature of internal refractory material and wind pressure have effect on the strain gauge. However, static pressure value is required to compensate. To solve these problems, this paper suggests finding relationship between Hearth Liquid Level and strain gauge output, adding digital filter in strain gauge. Using the proposed method, it was possible to estimate the hearth liquid level and determine the appropriate tapping time. Usefulness of the proposed method through simulations and experimental results are confirmed.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2004.11a
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• pp.203-206
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• 2004

본 논문에서는 오디오 워터마킹 기술을 이용하여 중앙방송국과 지방방송국간의 방송전환을 용이하게 할 수 있는 시스템을 구현하였다. 방송전환을 위한 동기화 시스템에서의 오 검출은 방송사고를 일으키기 때문에, 오디오 워터마크기술을 이용할 때 신뢰성이 매우 높아야 한다. 달 논문에서는 방송동기화 시스템에 효율적으로 적용할 수 있는 오디오 워터마킹 알고리즘을 개발하고, 이를 실시간으로 적용하여 방송전환에 사용할 수 있는 시스템을 구현하였다. 개발된 오디오 워터마킹 알고리즘에 의해서 워터마크가 삽입된 방송신호의 SNR은 66.1dB로서 워터마크 삽입전의 방송신호와의 구분이 어려웠다. 강인성 테스트에서는 96kbps와 128kbps의 MP3 압축을 하였을 때에도 $100\%$의 검출율을 보였으며, -50dB 이하의 잡음첨가에 대해서도 $100\%$ 검출율을 보였다. 구현된 시스템은 240시간의 실제 방송상황에서 워터마크가 삽입된 방송신호에 대한 검출율이 $100\%$이고, 오검출율이 $0\%$로 방송시스템으로서의 신뢰성을 확보하였다.

• Journal of Broadcast Engineering
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• v.5 no.1
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• pp.2-9
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• 2000

This paper presents a statistical motion activity description method and video retrievals by using the intensity and directions of the extracted motion vectors from video sequence. Since the proposed method can represent temporal and spatial cognitive characteristics of an entire video, several images between key frames, and images in a certain interval, it can be effectively applied to digital video services such as video retrieval, surveilance, multimedia database, and broadcasting filterings. In the paper, the effectiveness of the proposed algorithm is shown with a lot of shots of MPEG-7 video dataset.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.2
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• pp.141-149
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• 2010

It is essential to find oscillating angles and periods in a seaway when designing and manufacturing stabilizers. It is difficult to find oscillating angles and periods in high speed turning and they vary with ship speed and wave heading angles, therefore, proper algorithm to measure oscillating periods in a seaway. In the present study, three kinds of algorithms are developed to measure oscillating angles periods in a seaway. Dual axis tilt sensor of low price is used to measure oscillating angles, and the effect of lateral accelerations on tilt sensor have been reduced by the fusion algorithm using the gyro sensor signals. Analog and digital filters are applied to minimize the noise of the signals. Three kinds of algorithms, zero crossing, peak to peak and moving zero crossing algorithm, are developed to measure oscillating periods in a seaway. It is found that the moving zero algorithm showed the best results in the sea trials.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.3
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• pp.219-223
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• 2008

The dissolved oxygen (DO) sensors were fabricated by screen printing method, and potable dissolved oxygen measurement system was fabricated for low cost products. The fabricated sensors had high current change and fast response according to dissolved oxygen concentrations in the applied voltage of 0.7 V. The DO measurement system was consisted of MCV, amplifier, filter, power supply and display. DO concentrations were programed to display as digital percentages by converting the analog value. It is expected that the fabricated DO measurement system can replace the expensive commercial DO meter, because it reveals the high accuracy of ${\pm}0.5%$ to the standard solution and the response time of about 100 sec like the commercial DO meter.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.817-818
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• 2006

In Magnetic Resonance Imaging(MRI), the QRS complex of ECG is used as a trigger signal for MRI scan. But, gradient and RF(radio frequency) artifacts which are caused to static and dynamic field in MRI scanner cause interference in the ECG. Also, the signal shape of theses artifacts can be similar to the QRS-complex, causing possible misinterpretation during patient monitoring and false gating of the MRI. In case of using general FIR or IIR band-pass filters for minimizing the artifacts, artifact-reduction-ratio is not excellent. So, an adaptive real-time digital filter is proposed for reduction of noise by gradient and RF(radio frequency) artifacts. The proposed filter for MRI-Gating is based on the noise-canceller with NLMS(Normalized Least Mean Square) algorithm. The reference signals of the adaptive noise canceller are a combination of the noisy three channel ECG signals. In conclusions, the proposed method showed the acceptable quality of ECG signal with sufficient SNR for gating the MRI and possibility of real time implementation.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1099-1106
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• 2017

In this paper, a three phase inverter control methodology for photovoltaic generation system, which is a renewable energy source, was studied. The voltage source inverter type of the constant voltage supply type was selected as the three phase photovoltaic inverter, and SWPM method was selected as control technique. a small capacity three phase photovoltaic inverter system, which has a DSP with powerful high speed data processing ability as the main controller and a solar controller as current controller to supply a certain amount of current to charge the battery, was made and tested for SPWM function.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.307-310
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• 2001

In this paper we describe the design and implementation of uplink receiver for BWLL base station modem. The demodulator consists of digital down converter, matched filter and synchronization circuits. For symbol timing recovery we use Gardner algorithm. And we use forth power method and decision directed method for carrier frequency recovery and phase recovery, respectively. For the sake of performance analysis, we compare simulation results with the board implemented by FPGA which is APEX20KE series chip for Alter. The performance results show it works quite well up to the condition that a frequency offset equal to 4.7% of symbol rate.1

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1147-1152
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• 2004

This paper presents the design of a multi-standard NTSC/PAL video encoder. The encoder converts International Telecommunication Union-Recommendation (ITU-R) BT.601 4:2:2, ITU-R BT.656 or RGB inputs from various video sources into National Television Standards Committee (NTSC) or phase-alternate line (PAL) TV signals in both S-video and composite video baseband signals (CVBS). The encoder adopts multiplier-free structures to reduce hardware complexity. The hardware bit width of programmable digital filters for luminance and chrominance signals, along with other operating blocks, are carefully determined to produce high-quality digital video signals of 1 least significant bit (LSB) error or less. The proposed encode. is experimentally demonstrated by using the Altera APEX20K600EBC652-3 device.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.5
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• pp.582-589
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• 2016

Multi-mode monopulse system is widely used for satellite terminal like UAV because of high tracking accuracy and low size/weight profile. In order to calculate tracking error, Multi-mode monopulse system utilizes high-order mode signal, and it should have enough C/N(carrier to noise) level therefore tracking system needs narrow band filtering of received satellite beacon signal as much as possible. However, UAV suffers for beacon frequency drift derived from Doppler effect due to satellite figure 8 movement and UAV maneuvering. Therefore wideband signal processing needs to be considered in advance for exact doppler compensation and consequent time delay. In this paper, we propose the multi-stage Digital Signal processing system for beacon signal, which could minimize the signal delay under high Doppler and low C/N condition.