• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.982-986
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• 1997

A method using cutting force signal and neural network for detection tool damage is proposed. Cutting force signal is gained by tool dynamometer and the signal is prepocessed to normalize. Cutting force signal is changed by tool state. When tool damage is occurred, cutting force signal goes up in comparison with that in normal state. However,the signal goes down in case of catastrophic fracture. These features are memorized in neural network through nomalizing couse. A new nomalizing method is introduced in this paper. Fist, cutting forces are sumed up except data smaller than threshold value, which is the cutting force during non-cutting action. After then, the average value is found by dividing by the number of data. With backpropagation training process, the neural network memorizes the feature difference of cutting force signal between with and without tool damage. As a result, the cutting force can be used in monitoring the condition of cutting tool and neural network can be used to classify the cutting force signal with and without tool damage.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.3
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• pp.384-388
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• 1986

This paper describes the design and fabrication of an integrated circuit that can detect the teletext signal included in a composite video signal. The circuit that is based on the comparatorlevel sampling method can detect a stable data signal even from an external circuit with large variation. It has been fabricated by the SST bipolar standard process. Its chip size is $2.5x3.78mm^2$.

• Proceedings of the KWS Conference
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• 2002.05a
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• pp.65-67
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• 2002

The gas metal arc welding(GMAW) is regarded as one of the best candidate for welding automation in industrial joining application. It is important to monitor the weld quality for the high performance of weld automation. The measured analog signal is frequency analyzed by digital signal process method. In order to observe the welding phenomena and control welding condition, arc light, voltage, and current are measured at the same time. They are analyzed and compared with arc sound. for these experiments, a power source of constant voltage characteristics was used in the pure metal transfer mode.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.29-30
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• 2001

MAP kinase/ AP-1 signal transduction components are rapidly initiated by many extracellular stimuli, especially environmental carcinogens. We have investigated the role of MAP kinases (Erks, JNKs, and p38 kinases) and AP-1 signal transduction pathways in the process of cell transformation and carcinogenesis. Incubation of Cl 41 cells with tumor promoters such as TPA, EGF, arsenic, or TNF-$\alpha$ led to cell transformation and activation of MAP kinases.(omitted)

• ETRI Journal
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• v.27 no.4
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• pp.453-456
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• 2005

The ultra-wideband (UWB) signal radiation process in an antenna is different from that of a narrowband signal. In this paper, we study the degradation of the desired signal component according to the antenna structure and location of a receiver in a bipolar time-hopping UWB system. And we propose a receiver structure with an adaptive template waveform generator to compensate for the degradation caused by a realistic TX-RX antenna system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.10
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• pp.2001-2013
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• 1994

In this paper, the method of processing a blurred noisy image has been researched. The conventional method of processing signal has faluts which are slow convergence speed and long time-consuming process at the singular point and or in the ill condition. There is the process, the Gauss Seidel's method to remove these faults, but it takes too much time because it processed singnal repeatedly. For overcoming the faults, this paper shows a image restoration method which takes shorter than the Gauss-Seidel's by comparing the Gauss Seidel's with proposed alogorithm and accelerating convergence speed at the singular point and/or in the ill condition. In this paper, the conventional process method(Gauss-Seidel) and proposed optimal algorithm were used to get a standard image($256{\times}56{\times}bits$). and then the results are simulated and compared each other in order to examine the variance of MSE(Mean Square Error) by the acceleration parameter in the proposed image restoration. The result of the signal process and the process time was measured at all change of acceleration parameter in order to verify the effectveness of the proposed algorithm.

• Journal of the Korean Magnetics Society
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• v.1 no.2
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• pp.74-78
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• 1991

The method for analyzing the recording and reading process of magnetic recording system by numerical simulation is introduced. which can simulate the effect of elements of the magnetic recording system. During the whole simulation, hysteresis characteristics must be included. Preisach model and finite element method are used to construct the algorithm. From the wave of recording current, recorded pattern of magnetization in recording media is simulated in recording process, and then waveform of reading signal in head coil is obtained in reading process. To show the validity of this method, this is applied to perpendicular magnetic recording system. Waveform of recording signal and reproduced signal is obtained in several density. Pattern of reprocuced voltage magnitude according to increase of recording density shows roll-off curve.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.4
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• pp.330-336
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• 2014

The continuous chip generated in cutting process deteriorates workpiece, tool, and machine tool system. It is necessary to treat this continuous chip in ductile material machining condition for stable cutting. This paper deals with the chip control method using acoustic emission(AE) signal in pure copper turning operation. AE raw signals, root mean square(RMS) signals and wavelet transformed signals measured in turning process are introduced to analysis for chip patterns. With analysis of AE signals, it is obtained that the produced chip patterns are correlated with the specified AE signals which are transformed by fuzzy pattern algorithm. By this experimental investigation, the chip patterns can be classified at significant level in pure copper machining process and controlled from continuous chips to reduced-length stable chips.

• Journal of Biomedical Engineering Research
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• v.16 no.4
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• pp.403-414
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• 1995

It is very difficult to quantize the ECG analysis because the decision criterion for ECG is different with each other depending on the medical specialists of the heart and there are measured detecting errors for each ECG measurement system. Therefore, we developed the real-time ECG identification system using digital fuzzy processor for STD-BUS, in order to reduce ambiguity generated in the process of ECG identification and to analyze the irregular ECG stastically to ECG's repetition interval. The variables such as AGE (months), width of QRS, average RRI, and RRI were used to classify the ECG, and were applied to ECG signal indentification system which is developed for the purpose of research. It was found that the automatic diagnosis of ECG signal was possible in the real time process which was impossible in general process of algorithm.

• JSTS:Journal of Semiconductor Technology and Science
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• v.5 no.4
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• pp.276-281
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• 2005

This paper presents a low voltage operating IF QPSK receiver block which is consisted of programmable gain amplifier (PGA) and analog to digital converter. This PGA has 6 bit control and 250MHz bandwidth, $0{\sim}20\;dB$ gain range. Using the proposed PGA architecture (low distortion gain control switch block), we can process the continuous fully differential $0.2{\sim}2.5Vpp$ input/output range and 44MHz carrier with 2 MHz bandwidth signal at 1.8V supply voltage. Using the sub-sampling technique (input freq. is $44{\sim}46MHz$, sampling freq. is 25MHz), we can process the IF QPSK signal ($44{\sim}46MHz$) which is the output of the 6 bit PGA. We can get the SNDR 35dB, which is the result of PGA and ADC at full gain mode. We fabricated the PGA and ADC and the digital signal processing block of the IF QPSK with the 0.18um CMOS MIM process 1.8V Supply.