• Journal of the Institute of Convergence Signal Processing
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• v.14 no.3
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• pp.154-161
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• 2013

In this paper, Gabor cosine and sine transform considered as human visual filter is applied to watermarking methods for digital images. Four algorithms by using singular values or principal components of SVD in the frequency domain are proposed for watermark embedding and extraction. Two dimensional image is used as an embedded watermark. To measure the similarity between the embedded watermark image and the extracted one, a normalized correlation value is computed for the comparison of the four proposed methods with various attacks. Extracted watermark images are also provided for visual inspection. The proposed GCST-SVD method which embeds a watermark image into the lowest vertical or horizontal ac frequency band can provide useful watermarking algorithm with high correlation values and visual watermark features from experimental results for various attacks.

• Journal of Biomedical Engineering Research
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• v.17 no.2
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• pp.221-226
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• 1996

Tendon reflex responses generated from mechanical stimulus had been studied for quantitative analysis of activity of tendon reflex, especially patellar tendon reflex responses are known to be a criterion for diagnosing the L3 or L4 radiculopathy. In this paper, we developed a digital signal processing system for analysis of the tendon reflex response. The system parameter, i.e., $\textit{sampling frequency, pre-amplification gain, input channel and filter bank}$ are selected by Using software switches. From the view points of flexibility, the system hardware is connected to an IBM PC for analyzing the tendon reflex parameters, amplitude, latency duration We applied the proposed system to the analysis of the patellar tendon reflex reponses. In the experiment, we measured latency, duration, amplitude of the reflex action potentials generated from vastus medialis, vastus lateralis and rectus femoris that compose quadriceps, and the measured data are analyzed througll the ANOVA test which has 5% significant level. As a result, we showed that the mean amplitude of reflex action potential at the vastus lateralis is larger than any other muscle and the mean latency of the reflex action potential at the rectus femoris is shorter than any other muscle.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.191-191
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• 2000

Hydraulic servo system is difficult to be made up and each component is very expensive, it takes long for actual system to make and test and it costs a high price. Because of these characteristics of hydraulic servo system, a real time simulator that could describe behavior of real system is highly demanded, without composing real hydraulic system. So, many studies have been (lone on these subjects and many simulators are developed with superiority. Since the nonlinearity of a hydraulic system common simulator have composed of many calculative times byusing DSP(Digital Signal processing) and have made it possible to find the situations of the system in real time, calculating hydraulic simulation and controller separately. In this study, we suggest real-time simulator that could describe real system without ordinary DSP card. This simulator is composed of 80196kc and personal computer. DSP card that has calculated complex numerical equation is supplanted by personal computer and 80196kc generates control signals independently out of the personal computer. In all process, personal computer is synchronized with one-board microprocessor within sampling time in the closed loop system. This makes it possible to be described in hydraulic servo system in real time. And to make a comparison between the result of the real-time simulator and a hydraulic servo system.

• Journal of the Institute of Convergence Signal Processing
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• v.8 no.3
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• pp.163-170
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• 2007

In this paper, we propose that the polyphase scaler whose performance to that of the bicubic method, has less complexity in hardware structure. In order to get the new information, proposed system is based on the group delay which is one of the digital filter characteristics. The performance of this system is superior to that of bicubic algorithm which is well known. Because the hardware structure is simpler than other image scalers, we can adopt this system for mobile devices easily. The previous polyphase filters make blurring noise which is generated by up-scaling. We replace polyphase filters by boost-up filter to get vivid image. The proposed scaler is verified by Xilinx Virtex2 FPGA and is used as digital Boom in mobile camera phone.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.2
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• pp.225-232
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• 2017

Recently, the development of digital transmission technology of audio signals and the introduction of audio network equipment using digital transmission technology have been made. As a result, audio network technology and equipment are actively applied to the design and construction of audio systems. The meeting room is a place where a large number of participants exchange opinions and communicate with each other. In addition to using an electric acoustic device such as a microphone and a speaker, it improves the intelligibility of the conference room through an example using an audio network.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.11
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• pp.62-71
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• 2002

This paper presents new DSP (Digital Signal Processor) instructions and their hardware architecture for high-speed FFT. the instructions perform new operation flows, which are different from the MAC (Multiply and Accumulate) operation on which existing DSP chips heavily depend. The proposed DPU (Data Processing Unit) supporting the instructions shows two times faster than existing DSP chips for FFT. The architecture has been modeled by the Verilog HDL and logic synthesis has been performed using the 0.35 ${\mu}m$ standard cell library. The maximum operating clock frequency is about 144.5 MHz.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.681-683
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• 2017

In the digital information age, image processing is essential for various digital devices such as smart phones, cameras, and TVs. However, degradation occurs in analyzing, recognizing, and processing image data, and salt & pepper noise occurs. Therefore, in this paper, we applied linear interpolation method, newton interpolation method, lagrange interpolation method, and spline interpolation method to the image damaged by salt & pepper noise in order to find more effective interpolation method in salt & pepper noise environment, The methods were compared using the PSNR (peak signal to noise ratio).

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.3
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• pp.97-103
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• 2014

Recently, digital door locks have been widely used as physical security devices for the door. Although they are convenient compared to the existing lock system, they have the problem of being opened by an electric shock. In this study, to improve safety, a method to hide the door-lock device inside and to display the door-lock on a user's smart-phone screen through the augmented reality is suggested. Furthermore, an additional function has been added which provides memo notes to facilitate communication among family members. The results of this study have been implemented by using motors to control locks, Wi-Fi shield, Arduino, and a virtually created door and showed desirable experimental results.

• Journal of the Institute of Convergence Signal Processing
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• v.14 no.2
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• pp.82-89
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• 2013

A detection method of high precision digital line within image is proposed in this paper. If we set the size of image to $N{\times}N$, in fact it is difficult to use the resulting values that the amount of computation is $O(N^4)$. Multiple algorithms are examined to reduced the amount of computation to $O(N^3)$, while suppressing the degradation of precision. How to detect line from the image processing, after stretching treatment of line segments extracted by Hough transform in the local area of an image is a great way to be able to detect several long or short line at high speed, but this method is slightly less precision in the detection of tilted line segments. In this paper, a line detection method improving the precision detection of tilted line segment is applied to the local area, thereby this method does not reduce the processing speed, while it is high precision method for detecting line segments. The experimental results confirm that the proposed method can detect a high precision line in a shorter period of time, compared with the existing methods.

• Korean Journal of Optics and Photonics
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• v.24 no.5
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• pp.245-250
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• 2013

The Wiener-Khinchin theorem, which means that the autocorrelation function of a signal corresponds to the power spectrum of the signal, is very important in signal processing, spectroscopy and telecommunications engineering. However, because of needs for some relatively expensive equipments such as a correlator and the signal processing system, its demonstration in most undergraduate class is not easy so far. Recently, digital oscilloscopes whose functions can be replaced foresaid equipments are marketed with development of digital engineering. In this paper, a simple demonstration of the theorem is given by a digital storage oscilloscope and a personal computer with its theoretical background. The reason that deals again with this theorem which has been introduced in 1930 is that it has been not well informed yet to us and theoretical background of the demonstration is directly introduced from its driving process. Through deriving process of the theorem, some extended physical meanings of the impedance, power, power factor, Wiener spectrum, linear system response and, furthermore, basic idea of the Planck's quantization in the black body theory reveal themselves naturally. Hence it can be referred to lectures in general physics, modern physics, spectroscopy and material characterization experiment.