• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.39-42
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• 2008

In this paper, we analyze the performance of ultra wide band (UWB) systems in indoor wireless channel in accordance with the number of pulses per bit at transmit signals and the decision types of receiver. The indoor channel is modeled as the modified Saleh and Valenzuela (SV) model which has been proposed as a UWB channel model by the IEEE group, IEEE 802.15.SG3a. Two types of UWB signals are considered One is the pulse position modulation-time hopping (PPM-TH) signal. And the other is the pulse amplitude modulation-direct sequence (PAM-DS) signal. It is assumed that the receiver is an ideal receiver which can receive all signals of the multipath.

• Korean Journal of Oriental Medicine
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• v.15 no.2
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• pp.101-109
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• 2009

The Pulse diagnosis is in the boundary of the Four Examinations, and it is called 切診, or palpation. It has a great impact on people in reminding of the Traditional Medicine that it is probably the first thing that people think of when they hear about Traditional Medicine. Hu-Jun quoted in the Treasured Mirror of Eastern Medicine "東醫寶鑑" that the doctor finds out the deficiency and the excess of the meridian of the patiant through the pulse, and that it is of the utmost necessity to know the "deficiency and the excess" of the meridian to decide the formula (君臣佐使) of the herbal medicine and the acupuncture/moxibustion treatment. The research on the studies of pulse diagnosis have been concentrated on the origin, history, and the theory of the pulse diagnosis throughout the years; however, the number of research on the image from the classics on pulse diagnosis have been less. With this in mind, this paper was written to study more on the origin and the history of the pulse diagnosis as well as to study on the image of pulse diagnosis shown on the classics on Traditional Medicine in China and Korea. The history of the pulse diagnosis has its root on the attempt to find out what is happening inside the body through the indication of the small changes of the pulse that is shown on the outer boundaries of the body. There were various kinds of pulse diagnosis including "Three positions and nine indicators method" and "Carotid pulsation and wrist pulse method" in the ancient period, and wrist pulse-taking method became the most popular since the completion of studying on palpation by 初보. The image of the palpation helps the rudimentary practitioners of Traditional Medicine. They are divided into two large categories, which are the area of diagnosis and the shape of the pulse itself. The historical classics including the image of the pulse diagnosis can be found since the Song Dynasty of China. There are various kinds of image of pulse diagnosis in the classic such as "The picture of the hand meridian" from "脈訣指掌病式圖說", "The picture of the image of meridian" from "察病指南", "The picture of the Seven exterior and Eight interior" from "校正圖注脈訣", and "The picture of the six parts of meridian" from Treasured Mirror of Eastern Medicine "東醫寶鑑". The Treasured Mirror of Eastern Medicine "東醫寶鑑" have analyzed the basic theories and made up the standards of pulse diagnosis by establishing "The picture of the six parts of meridian" based on "The method of placing the viscera and bowels corresponding to cun-guan-qi, or the meridian".

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6114-6118
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• 2013

This study examined the ultrasonic pulse reflection method(UPRM) for testing each ultrasonic pulse waveform model(UPWM) based on weld defects. The sharp crack of a clear signal was generated. The echo height of the defective probes changed according to the location. In a long crack in a circle around the defective probes, the Swivel scanning echo height when using the particle was reduced drastically. The peaks in the echo were thin because the needle was pointed. The porosity defects arising from a single echo was sharp and crisp, but a number of pores of the collective reflection overlapped and ajagged echo was observed. Slag, slag inclusions, cracks, and defects at the Swivel scan of each particle using the echo shape showed difference in the degree. Cracks were revealed as sudden changes in the echo height of the slag inclusions: increase ${\rightarrow}$ decrease ${\rightarrow}$ increase ${\rightarrow}$ decrease. In addition, the location of a number of defects in the dense pore geometry, such as a typical echo sundry, revealed the shape in the slag. Poor penetration of the defect echo, revealed the cracks to have a sharp-edged, crack-like shape with an echo.

• Korean Journal of Materials Research
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• v.27 no.11
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• pp.624-630
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• 2017

In this study, we investigated the overpotential of precipitation related to the catalytic activity of electrodes on the initial process of electrodeposition of Co and Co-Ni alloys on polycrystalline Cu substrates. In the case of Co electrodeposition, the surface morphology and the magnetic property change depending on the film thickness, and the relationship with the electrode potential fluctuation was shown. Initially, the deposition potential(-170 mV) of the Cu electrode as a substrate was shown, the electrode potential($E_{dep}$) at the $T_{on}$ of electrodeposition and the deposition potential(-600 mV) of the surface of the electrodeposited Co film after $T_{off}$ and when the pulse current was completed were shown. No significant change in the electrode potential value was observed when the pulse current was energized. However, in a range of number of pulses up to 5, there was a small fluctuation in the values of $E_{dep}$ and $E_{imm}$. In addition, in the Co-Ni alloy electrodeposition, the deposition potential(-280 mV) of the Cu electrode as the substrate exhibited the deposition potential(-615 mV) of the electrodeposited Co-Ni alloy after pulsed current application, the $E_{dep}$ of electrodeposition at the $T_{on}$ of each pulse and the $E_{imm}$ at the $T_{off}$ varied greatly each time the pulse current was applied. From 20 % to less than 90 % of the Co content of the thin film was continuously changed, and the value was constant at a pulse number of 100 or more. In any case, it was found that the shape of the substrate had a great influence.

• The Journal of the Korea Contents Association
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• v.10 no.2
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• pp.72-80
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• 2010

The 1Gbps clock and data recovery (CDR) circuit using the proposed multi-point phase detector (PD) is presented. The proposed phase detector generates up/down signals comparing 3-point that is data transition point and clock rising/falling edge. The conventional PD uses the pulse width modulation (PWM) that controls the voltage controlled oscillator (VCO) using the width of a pulse period's multiple. However, the proposed PD uses the pulse number modulation (PNM) that regulates the VCO with the number of half clock cycle pulse. Therefore the proposed PD can controls VCO preciously and reduces the jitter. The CDR circuit is tested using 1Gbps $2^{31}-1$ pseudo random bit sequence (PRBS) input data. The designed CDR circuit shows that is capable of recovering clock and data at rates of 1Gbps. The recovered clock jitter is 7.36ps at 1GHz and the total power consumption is about 12mW. The proposed circuit is implemented using a 0.18um CMOS process under 1.8V supply.

• Journal of the Korean Society of Radiology
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• v.11 no.3
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• pp.139-146
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• 2017

At the Brain MRI examination, RF Pulse are irradiated on the human head in order to acquire MR images. At this time, a considerable part of the irradiated RF Pulse energy is absorbed in our body and the temperature of the human head will rise depending on the degree of exposure, so it will affect the human head. Even if the same RF Pulse energy is given, if the metal is inserted in the human head, the conductivity of the human head is greatly increased by the metal, so the SAR value increases and the temperature also rises. Therefore, we started this research with the question as to whether there is difference between the change in SAR value and temperature displayed on the head of the human according to use or not of the dental implant. Experiments were using the XFDTD program on a 128 MHz RF Pulse frequency by a 3.0 tesla MRI. We can see that both are increasing that the average value of SAR and temperature that absorbed by the human head model used the dental implant. In addition, the average maximum SAR value and the maximum temperature rise in the brain part are shown below the international safety standard value but the influence can not be ignored because of the result may change according to the increase in the number of dental implant. And as future tasks. we need to the simulation of temperature rise and SAR due to an increase in the number of implants and volumes of teeth, dental implant material.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.499-500
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• 2006

The electrode wear in micro-EDM significantly deteriorates the machining accuracy. In this regard, electrode wear needs to be compensated in-process to improve the product quality. Therefore, there are substantial amount of research about electrode wear. In this study a control method for micro-EDM using discharge pulse counting is proposed. The method is based on the assumption that the removed workpiece volume is proportional to the number of discharge pulses, which is verified from experimental results analyzing geometrically machined volume according to various number of discharges. Especially, the method has an advantage that electrode wear does not need to be concerned. The proposed method is implemented to an actual micro-EDM system using high speed data acquisition board, simple counting algorithm with 3 axis motion system. As a result, it is demonstrated that the volume of hole machined by EDM drilling can be accurately estimated using the number of discharge pulses. In EDM milling process a micro groove without depth variation caused by electrode wear could be machined using the developed control method. Consequently, it is shown that machining accuracy in drilling and milling processes can be improved by using process control based on the number of discharge pulses.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.4
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• pp.213-219
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• 2021

The submarine's intercept pulse detection detects pulses radiated from enemy surface ships, submarines, and torpedoes, and performs an important function of providing maneuverability and survivability of submarine. Whether or not the intercept pulse is detected is determined by comparing the size of the received pulse with the threshold value by the operator. In the case of intercept pulses, the intensity of the pulses is frequently reduced under the influence of various environmental factors. In the situation, if detection is performed with a fixed threshold, a non-detection problem occurs and persists until the operator sets a low threshold. In this paper, we proposed method for automatically adjusting threshold to reduce the non-detection problem caused by a fixed threshold. Simulation were preformed on 4 cases with different pulse level fluctuation widths, and it was confirmed that the detection performance was improved by increasing the number of detections when a method for automatically adjusting threshold was applied to all cases. Through the proposed method, it is expected that the intercept pulse detection performance will be improved in the marine environment the large fluctuations in pulse level in the future.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.3
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• pp.93-98
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• 2003

With the improvement of digital signal processors, digital pulse compressor(DPC) is widely used in radar systems. The DPC can be implemented by using FIR filter algorithm in time domain or FFT algorithm in frequency domain. This paper designs an expansible DPC using multiple DSPs. With ADSP-21060 of Analog Devices Inc., the computation time as a function of the number of received range cells and FIR filter tap is compared and analyzed in time domain using C-language and assembly language. therefore, when radar system parameters are determined, the number of DSP's required to implement DPC can be easily estimated.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.5
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• pp.253-259
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• 2005

Magnetic encoder with relatively low pulse per rotation is generally used for detecting speed of the high-speed rotating machine. It is due to the fact of the mechanical problems of vibration and bearing stiffness and also the limit of maximum output pulse of the mounted encoder. The magnetic encoder is divided into two types, that is, toothed gear-wheel method and magnetic wheel method according to the shape of the rotation disk. In case of detecting speed by the tooth gear-wheel, the encoder itself can be acted as the additional inertia where the number of tooth determining the output pulse and the width of the wheel detecting the change of the magnetic flux density are relatively enough large considering the volume of the rotating machine. While the magnetic wheel method has the limit of the magnetizing number of the ring magnet, there is relatively few, if nv, the influence of inertia on the machine. In this paper, it is proposed a simple magnetic wheel encoder suited for the high speed rotating machine and the method of signal processing and the output characteristics are examined through the V/F operation of max 48,000(rpm) and 2.4(KW) spindle motor.