• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.6
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• pp.1438-1446
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• 1996

Infrared seekers using reticles with a single detector have been widely used due to small size and low cost. However, the analysis of the error signals and the performance in multiple targets are performed either simplistically or not at all. In this paper, we present detector signals and processing results using image and signal processing techniques, especially performance analysis in multiple targets. The simulation results are essential to make the advanced signal processing part of retical seekers which can deal with various engagement scenarios.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.12
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• pp.31-44
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• 1996

Since optical delay line signal processing which utilizes optical fiber as delay line elements can provide high speed and broadband signal processing, the optical delay line signal processing has numerous applications. Recently, many research papers which optical delay line signal processing techniques are being applied to OCDMA are published. The author has published paper on the design method for optical fiber filters of lattice structure. However, the previous design method does not realize the transfer function all the time. It can be realized with constraints. In this paper, we propose the design method that can realize the transfer function all the time without any constraints for the optical fiber filter of lattice structure.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.1
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• pp.13-17
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• 2004

In order to measure the retina thickness, the retina photographing system and the multi-channel high speed image data acquisition system is developed. This system requires the optical processing techniques and the high speed image processing techniques. The HeNe laser beam is projected the retina in artificial eye and then we sensed the reflected laser signal using APD array. The laser projection system on retina using optical instruments is implemented. In order to project the plane laser beam on retina, laser photographing system used the polygon mirror for horizontal scanning and the galvano mirror for vertical scanning. We acquired retina images in each channel of APD array, transferred computer using PCI interface the image data after real-time A/D converting.

• The Journal of the Acoustical Society of Korea
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• v.20 no.2
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• pp.86-92
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• 2001

Various array processing techniques to identify the noise source position or bearing have been developed. Typical array processing techniques which are based on time delay between received signals at two sensors, are classified as conventional beamforming, correlation function and NAH (Near-Field Acoustic Holography) techniques which have their own characteristics with respect to application field and signal processing method. In this study, correlation function technique which could be applied for broadband noise source detection, is adopted and the effective detection technique is proposed considering the effects of source bandwidth and measurement noise correlation of noise sources. The validity of the Proposed technique is evaluated using the 3-dimensional nonlinear any which does not give 3-dimensional Position or bearing ambiguity

• Journal of the Institute of Convergence Signal Processing
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• v.14 no.2
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• pp.70-76
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• 2013

In this paper, we propose the bandpass form of discrete prolate spheroidal sequences(DPSS) which have the maximal energy concentration in a given passband and as such are very appropriate to obtain a projection of signals. The basic properties of the bandpass DPSS are also presented. Assuming a signal satisfies the finite time support and the essential band-limitedness conditions with a known center frequency, signal representation and interpolation techniques for band-limited signals using the bandpass DPSS are introduced where the reconstructed signal has minimal out-of-band energy. Simulation results are given to present the usefulness of the bandpass DPSS for efficient representation of band-limited signal.

• The Journal of the Korea institute of electronic communication sciences
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• v.3 no.2
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• pp.65-70
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• 2008

Digital signal processing (DSP) is the process of taking a signal and performing an algorithm on it to analyze, modify, or better identify that signal.[1] To take advantage of DSP advances, one must have at least a basic understanding of DSP theory along with an understanding of the hardware architecture designed to support these new advances. There are several programming techniques that maximize the efficiency of the DSP hardware, as well as a few fundamental concepts used to implement DSP software. This article introduced some of these underlying functions that are the building blocks of complex signal processing functions, and It will touch on the fundamental concepts of DSP theory and algorithms and also provide an overview of the implementation and optimization of DSP software, and discuss the development of DSP.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.828-831
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• 1996

Radiation monitoring system is needed at nuclear power plant and nuclear facility. Manual survey techniques are commonly used, but they are time consuming and somewhat inaccurate. Automatic radiation surveys are very important because it provides significant savings in men-rem and wages. Unmanned, remote automatic radiation measurement system should be small and light-weighted in order to mount on robotic system. The system we have developed consists of detection parts, signal processing part, interface, and software part. Position information is provided by using of a collimator. The measurement process is achieved by the scanning of detector and image processing techniques are used to display radiation levels. We designed collimators, detectors, signal processing circuit, and constructed prototype system. The goal of this system is the mapping of camera image and radiation level distribution.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.12
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• pp.2664-2673
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• 1997

The signal fading distortion has effect on the capacity of cellular mobile communication systems. The short term fading is solved by signal processing techniques depending on the radio communication methods, but another distortion compensation techniques are necessary to combat long term fading. in this paper, we have simulated the call processing in DS-CDMA system using distributed antennas to overcome the long term fading. From the simulation results, we have conformed that the blocking probability of a new call andthe forced probability of handoff-request-call have decreased by increasing the number of distributed antennas.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.334-337
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• 2005

The speech intelligibility is one of the most important factors in communication system. The speech intelligibility is related with speech to noise ratio. To enhance the speech to noise ratio, background noise reduction techniques are being developed. As a part of solution to noise reduction, this paper introduces directional microphone using beamforming method and speech filtering method. The directional microphone narrows the spatial range of processing signal into the direction of the target speech signal. The noise signal located in the same direction with speech still remains in the processing signal. To sort this mixed signal into speech and noise, as a following step, a speech-filtering method is applied to pick up only the speech signal from the processed signal. The speech filtering method is based on the characteristics of speech signal itself. The combined directional microphone and speech filtering method gives enhanced performance to speech intelligibility in communication system.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.535-538
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• 2001

In this paper, we present a novel method to solve the inevitable RGB beam mismatch problem in projection TV receivers. Conventional methods solve the mismatch problem by directly controlling the cathode ray tube (CRT) using the convergence yoke (CY). Unlike conventional methods, the proposed method is based on digital video processing using image warping techniques. Firstly RGB beam projection paths are mathematically modeled. Then based on the modeling, the input video signal to CRT is prewarped so that RGB beams are landed at the same point on the screen. Since the proposed method is based on a digital video processing instead of using CY, it can outperform the conventional method in terms of quality and cost. The experimental results with a real 60´projection TV demonstrate that the proposed method indeed produces converged images on the projection TV screen.