• The Journal of the Acoustical Society of Korea
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• v.18 no.1
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• pp.45-52
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• 1999

In this thesis, a packer is proposed and designed for removing the bottle-neck effect and easy signal processing using a new algorithm with the operation frequency of 54MHz. To verify the performance of the proposed packer, DCT coefficient encoding block with ROM table using a combinational logic is designed and its output data are used the input data of the packer. Circuits in this thesis are designed by using VHDL code and its modeling and simulation are performed by SYNOPSYS tool using $0.65{\mu}m$ rule.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.685-691
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• 1993

This paper introduces a PC-based image data processing unit that is composed of preprocessor board and main processor board; The preprocessor contains Inmos A110 processor and efficient H/W architecture for fast mask/logic operations at the speed of video signal rate. It is controlled by the main processor which communicates with the host PC. The main processor board contains TI TMS320C31 digital signal processor, and can access the frame memory of the processor for extra S/W tasks. We test 3*3, 5*5 masks and logic operations on 386/486/DSP and compare the result with that of the proposed unit. The result shows ours are extremely faster than conventional CPU based approach, that is, over several hundred times faster than even DSP.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1376-1378
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• 1999

Most conventional protection relays are based on processing information in the spectrum that is close to or at power frequency. It is, however, widely known that faults on transmission lines produce frequency components of a wide range In this respect, this paper describes the basis of a Protection technique for transmission lines which utilises high-frequency components. Fault-generated signals caused by post-fault and the signal derived from stack tuner is connected to the coupling capacitor of CVT. Digital signal processing is then applied to the captured information to determine whether the fault is inside or outside the Protected zone, and to discriminate the fault type on transmission line.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.70-72
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• 2005

The present paper designed a weight measuring instrumentation system in which data conversion and a series of signal processing were totally equipped. 16 loadcell are incoming sensors and each output of the loadcell was amplified and filtered for proper analog signal processing. Several measuring instrumentation OP amps and general purposed OP amps were used. 12 bits AID converters converted analog signals to digital bits and a PIC microprocessor controlled the 16 channels of loadcell. RF RS232 modules were used for wireless communication between the PIC microprocessor and an ethernet host for a remote sensor monitoring system development.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1026-1029
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• 2003

There are always some errors in force sensing of multi-axis force sensors that aggravate sensor performance. Error sources may be classified mainly in two groups. One is structural error due to inaccuracy of sensor body, and the other is error due to noise signals existing in the sensed information. This paper presents a brief review about the principle of multi-axis force sensors, and then a method that can reduce the effect of noise signals. The method is to read digital signals in computer instead of analog voltage signals. We can eliminate the bad effect of electromagnetic waves emitted from computer and of 60 Hz noise emitted from AC source by the proposed method. The proposed method is investigated through experimental demonstration. The experimental results show the proposed method improves the sensor performance significantly.

• Journal of the Institute of Convergence Signal Processing
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• v.14 no.1
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• pp.13-20
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• 2013

A combined DWT and DCT based watermarking technique of low frequency watermarking with weighted correction is proposed. The DWT has excellent spatial localization, frequency spread and multi-resolution characteristics, which are similar to the theoretical models of the human visual system (HVS). The DCT based watermarking techniques offer compression while DWT based watermarking techniques offer scalability. These desirable properties are used in this combined watermarking technique. In the proposed method watermark bits are embedded in the low frequency band of each DCT block of selected DWT sub-band. The weighted correction is also used to improve the imperceptibility. The extracting procedure reverses the embedding operations without the reference of the original image. Compared with the similar approach by DCT based approach and DWT based approach, the experimental results show that the proposed algorithm apparently preserves superiori mage quality and robustness under various attacks such as JPEG compression, cropping, sharping, contrast adjustments and so on.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2001.06a
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• pp.117-120
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• 2001

Deadbeat property is well established in digital control system design, But in continuous time, it can hardly realized for it's asymtotic property. But recently japanese researchers suggested serveral method for continuous time deadbeat property. They use delay elements In polynomials and established for the deadbeat condition. By solving this condition, unknown coefficients in polynomials with delay elements is obtained. In this paper, design method for optimal continuous time deadbeat servo system using 2nd order smooting elementsis studied. Continuous time deadbeat controller is consisted of serial integral compensator and local feedback one in state feedback loop. Determining method for damping rations and natural frequencies of smothing elements is described. By computer simulations, control inputs and system outputs are shown to have desirable property such as smoothness.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2001.06a
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• pp.69-72
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• 2001

High-level synthesis generates a structural design that implements the given behavior and satisfies design constraints for area, performance, power consumption, packaging, testing and other criteria. Thus, high-level synthesis generates that register-transfer(RT) level structure from algorithm level description. High-level syntehsis consist of compiling, partitioning, scheduling This paper we study the partitioning process, and analysis the min-cut algorithm and simulated annealing algorithm.

• Journal of Biosystems Engineering
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• v.24 no.1
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• pp.25-30
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• 1999

The effectiveness of many greenhouse environment control methodologies depends on the growth information of crops. Acquisition of the growth information of crops requires a non-invasive and continuous monitoring method. Crop growth monitoring system using digital imaging technique was developed to conduct non-destructive and intact plant growth analyses. The monitoring system automatically measures crop growth information sends an appropriate control signal to the nutrient solution supplying system. To develop the monitoring system, a linear model that explains the relationship between the fresh weight and the top projected leaf area of a lettuce plant was developed from an experiment. The monitoring system was evaluated buy successive lettuce growing experiments. Results of the experiments showed that the developed system could estimate the fresh weight of lettuce from a lettuce image by using the linear model and generate an EC control signal according to the lettuce growth stage.

• Journal of the Optical Society of Korea
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• v.3 no.2
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• pp.64-68
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• 1999

The performance of a fiber Bragg grating strain sensor constructed with 3$\times$3 coupler is investigated. A 3$\times$3 coupler Mach-Zehnder (M/Z) interferometer is used as wavelength discriminator, interrogating strain-induced Bragg wavelength shifts. Two quadrature-phase-shifted intensities are synthesized from the as-coupled interferometer outputs, and digital arctangent demodulation and phase unwrapping algorithm are applied to extract the phase information proportional to strain. Due to the linear relation between the input strain and the output of quadrature signal processing, signal-fading problems eliminated. In the experiment, a fiber grating that was surface adhered on an aluminum beam was strained in different ways, and the photodetector signals were transferred and processed in a computer-controlled processing unit. A phase recovery fo 7.8$\pi$ pk-pk excursion, which corresponds to ~650$\mu$strain pk-pk of applied strain, was demonstrated. The sensor system was stable over the environmental intensi쇼 perturbations because of the self-referencing effect in the demodulation process.