• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1630-1633
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• 2002

In this paper, we proposed a new control system of the dividing ratio changeable type ADPLL (DCPLL). The DCPLL has been designed by us. However, in the DCPLL, there are some problems such as this curcuit is increased the output jitter on multiple frequency, and the output jitter is large on steady state. Then, the output jitter characteristic on multiple frequency is improved by using “rest-control” system. Also, output jitter decreases by using “W-edge (positive edge h negative edge)” system. We confirmed some characteristics of the DCPLL with the circuit simulator, PSpice.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.11
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• pp.865-869
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• 2011

A cantilever-type piezoelectric generator has advantages of simple structure, ease of fabrication and large displacement by transverse vibration of a beam. It is easy to control the natural frequency, and also possible to increase the output power by changing the length, width, and thickness of the generator. In particular, the length increases, the natural frequency sharply decreases, and vice versa. Hence, the natural frequency can widely be controlled by using change in the length of elastic body. In this paper, the generator was designed and fabricated to change natural frequency using the slides of the case. In addition, the generating characteristics were confirmed through finite element analyses and vibration experiment. As a result, the maximum output characteristics could be generated due to resonance phenomenon although any frequency of external force was applied.

• Journal of the Korean Institute of Telematics and Electronics
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• v.10 no.3
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• pp.61-68
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• 1973

It was found that the rapidly changeable consonant's conlponents of the Korean speech can not be analyzed precisely by the method of frequency analysis, but only by the method of frequency synthesis based on the speech pattern obtained from sona-graph. The following two methods mer mainly: One was to extract the frequency region of Consortarts, and the other was to observe how the mode of the Formant of the Korean Vowel, $\mid$ㅏ$\mid$, following after some consonants. changes both by the articulation manner and by the articulation position.

• Journal of Sasang Constitutional Medicine
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• v.10 no.1
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• pp.215-233
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• 1998

The object of this study is 27 patients who had been treated in the Oriental Medical Hospital at Dong Eui Medical Center during 6 months from January 1998 to June 1998. We proceeded the judgment of Sasang Constitution by Questionaire of Sasang Constitution Classification II(QSCC II). The following conclusion were made in comparison with Questionaire of Sasang Constitution Classification II(QSCC II) and Questionaire of Pusan Sasang seminar. 1. The subject of "the facial type is small and sharp" is significant differences in Sasang Constitution classification. The frequency of Soeumin group is more than Taeumin group and Soyangin group. 2. The subject of "the walking form is fast and shake the body" is significant differences in Sasang Constitution classification. The frequency of Taeumin group and Soeumin group is less than Soyangin group. 3. The subject of "the skin type is white and thin" is significant differences in Sasang Constitution classification. The frequency of Soeumin group is more than Soyangin group, and the frequency of Taeumin group is low marks. 4. The subject of "the skin type is tender and dry" is significant differences in Sasang Constitution classification. The frequency of Taeumin group and Soyangin group is less than Soeumin group. 5. The subject of "the image of face is smart" is significant differences in Sasang Constitution classification. The frequency of Soeumin group is more than Taeumin group and the frequency of Soyangin group is low marks. 6. The subject of "the sweating type is not sweatier" is significant differences in Sasang Constitution classification. The frequency of Taeumin group and Soeumin group is less than Soyangin group. 7. The subject of "the desire of eating is changeable accoding to emotion" is significant differences in Sasang Constitution classification. The frequency of Soeumin group is more than Taeumin group and Soyangin group. 8. The subject of "the health is changeable accoding to the type of stool" is significant differences in Sasang Constitution classification. The frequency of Soeumin group is more than Soyangin group and the frequency of Taeumin group is low marks. 9. The subject of "the type of voiding is changeable accoding to the drinking when they have a fever" is significant differences in Sasang Constitution classification. The frequency of Taeumin group and Soyangin group is less than Soeumin group. 10. The subject of "the skin type is soft" is significant differences in Sasang Constitution classification. The frequency of Soeumin group is more than Taeumin group and Soyangin group. 11. The subject of "the chief complaint is the forgetfulness" is significant differences in Sasang Constitution classification. The frequency of Soeumin group is less than Taeumin group and Soyangin group.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.4
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• pp.193-203
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• 2001

The Monte Carlo method was used to evaluate the reliability of crash discrimination algorithms. Through the Fast Fourier Transformation, crash pulses obtained during frontal crash tests of a mini van and a sports utility vehicle were transformed to signals in the frequency domain, and the signals were divided into basic signals and changeable signals. The changeable signals were modified through random generation, and they were combined with the basic signals. Then, the combined signals were transferred back to the time domain. In this way numerous crash pulses could be generated. For the generated pulses, crash discrimination algorithms were evaluated by examining whether they did not result in air bag deployment for the pulses requiring no air bag deployment and whether they resulted in time-to-fires faster than required time-to-fires for the pulses requiring air bag deployment. The crash discrimination algorithm in which the absolute value of the deceleration change multiplied by the velocity change or the summation of the absolute value of the deceleration change was used as a metric was Proven to be highly reliable.

• 한국연소학회:학술대회논문집
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• 2004.11a
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• pp.152-160
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• 2004

Studies to investigate the influence on hydraulic acoustic wave were conducted using pressure swirl atomizer under making frequency range from 0 to 60Hz using water as a propellant. Pressure oscillation from hydraulic sources gives a strong influences on atomization and mixing processes. The ability to drive these low frequency pressure oscillations makes spray characteristics changeable. The effect of pressure perturbation and its spray characteristics showed that low injector pressure with pressure pulsation gives more significantly than high injector pressure with pressure perturbation in SMD, spray cone angle, breakup length. Moreover, this data could be used for prediction of low combustion instability getting G factor.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.394-402
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• 2009

To investigate the heavy-weight impact noise of apartment houses, numerical analysis was performed. The analysis acoustic pressure consider acoustic mode by finite element method. The variables considered effecting on the acoustic pressure are the Acoustic mode, acoustic damping, and the impulse load. The heavy-weight impact noise is a changeable value in the room. Since the most part of the frequency component of heavy-weight impact noise has low frequency. The noise in low frequency is related to the vibration of structure, the reflection of acoustic wave caused by wall and the standing wave called by acoustic mode. The prediction by the numerical analysis was verified with test result of the heavy weight-impact noise at apartment houses.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.265-267
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• 2003

The wavelet transform(WT) has been extensively applied in solving many problems in applied science and engineering following its introduction in early 1980's. The WT analyzes a signal in a changeable frequency range by employing a moving window whereby along time window is used to obtain low frequency information and short time window is used to obtain high frequency information. In this paper, after various fault types in 154 KV transmission system was simulated by using EMTP, and the RMS values by changing Mother wavelet was calculated by applying wavelet transform to the simulated voltage and current signal.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.4
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• pp.338-347
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• 1989

In this paper, the digital frequency synthesizer with the clock ccunting method is designed and implemented to increase the performace of the digital frequency synthesizer with pahse accumulating method which was developed before. Unlike an phase accumulating method, clock countind method is supplied a continually changeable clock frequency with PLL(Phase Locked Loop) and allocated a fixed phase step with N-ary counter. Form the experimenta results, it is confirmed that any periodic distorition phenomena are disappeared, and truncation harmonics are more reduced. But the output bandwidths are decreased in inverse proportion to the counter counting number and the circuits are somewhat complex than phase accumulating method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.5
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• pp.1610-1629
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• 2021

Failures frequently occurred in manufacturing machines due to complex and changeable manufacturing environments, increasing the downtime and maintenance costs. This manuscript develops a novel deep learning-based method named Multi-Domain Convolutional Neural Network (MDCNN) to deal with this challenging task with vibration signals. The proposed MDCNN consists of time-domain, frequency-domain, and statistical-domain feature channels. The Time-domain channel is to model the hidden patterns of signals in the time domain. The frequency-domain channel uses Discrete Wavelet Transformation (DWT) to obtain the rich feature representations of signals in the frequency domain. The statistic-domain channel contains six statistical variables, which is to reflect the signals' macro statistical-domain features, respectively. Firstly, in the proposed MDCNN, time-domain and frequency-domain channels are processed by CNN individually with various filters. Secondly, the CNN extracted features from time, and frequency domains are merged as time-frequency features. Lastly, time-frequency domain features are fused with six statistical variables as the comprehensive features for identifying the fault. Thereby, the proposed method could make full use of those three domain-features for fault diagnosis while keeping high distinguishability due to CNN's utilization. The authors designed massive experiments with 10-folder cross-validation technology to validate the proposed method's effectiveness on the CWRU bearing data set. The experimental results are calculated by ten-time averaged accuracy. They have confirmed that the proposed MDCNN could intelligently, accurately, and timely detect the fault under the complex manufacturing environments, whose accuracy is nearly 100%.