• Science of Emotion and Sensibility
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• v.18 no.3
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• pp.63-70
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• 2015

This study identified heart response of participants while listening to sounds which have 1/f fluctuations with exponent ${\alpha}$ gradient. The participants were engaged in emotional stress work. Prior studies related to 1/f fluctuation sound have reported that sound source can alleviate psychological and physiological state of users. Subjects of this study were exposed to sound with three levels of ${\alpha}$ gradient. Heart response of subjects were measured with Photoplethysmography(PPG) sensor simultaneously. The dependent variables of this study were beat per minute(BPM), very low frequency percent of pulse rate variability (VLF percent), the standard deviation of all normal RR intervals (SDNN), and high frequency power(HF power). Subject showed arousal response when exposed to sound with exponent ${\alpha}$ gradient of 3 whereas the sound with exponent ${\alpha}$ gradient of 1 and 2 resulted in relax effect. The characteristic of 1/f fluctuation sounds can be applied to alleviate stress for employers under emotional labor.

• Journal of Korean Society for Quality Management
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• v.50 no.2
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• pp.199-220
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• 2022

Purpose: The purpose of this study is to analyze the score data released by the Korea Institute of Curriculum and Evaluation to find out the problems with the current scoring system provided by the College Scholastic Ability Test and to suggest improvement measures to solve these problems. Methods: We calculated the descriptive statistics of the standard scores using the frequency distribution table of the standard scores and identified the characteristics of the standard scores by expressing the distribution as a graph. Also, we developed an index to evaluate whether each stanine level was stably assigned and calculated the indexes for each area/subject by using the data on the number of examinees for each level. Results: We found that the relationship of conversion from raw scores to integerized standard scores is different depending on the size of the standard deviation of the raw scores, and identified the problem that the raw score information is not fairly reflected in the calculation of the percentile and level as the two raw scores are converted to one standard score. This problem can be solved by calculating the standard score to a decimal point. Conclusion: In this study, as a way to improve the quality of the scores of the current CSAT, the standard score and percentile decimal notation, the specific regulations of the standard score and stanine level calculation method, and the expansion of the open range of the scores were suggested.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.179-182
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• 2006

This paper introduce a different-type voltage-controlled oscillator (VCO) for PLL frequency synthesizer, And also the architecture of a high speed low-power-consumption CMOS dual-modulus frequency divider is presented. It provides a new approach to high speed operation and low power consumption. The proposed circuits simulate in 0.35 um CMOS standard technology.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.6
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• pp.22-30
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• 1993

An integrated silicon pressure sensor with frequency output has been fabricated, measured, and tested. The standard bipolar process is applied and thin diaphragm was formed using EDP anisotropic etchant. Output frequency was 769 Hz-3.1 kHz at the pressure range of 0-10 psi. It operates at the temperature range of 0-50$^{\circ}C$. The frequency sensitivity was 233 Hz/psi and temperature sensitivity was 0.3 Hz/$^{\circ}C$. The power dissipation was 50mW.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.87-90
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• 1995

When the ultrasonic transducer operating at l MHz for use in cleaning semiconductor wafers or other industsrial materials is driven from the MOS-FET DC-to RF inverter, the output power severely depends on the frequency of operation since the quality factor of the transducer is high. In order to tune to the eresonating frequency of the ultrasonic transducer, the drive signal frequency of the MOS-FET power inverter is automatically scananed until the frequency is set at the resonating frequency of the ultrasonic transducer is maximized. The control circuit consists of an output power sensing circuit, a PLL controller, a frequency standard, and other peripheral circuits. The operation was satisfactory when the transducer having an output of 600 W at 1 MHz was used.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.121-122
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• 2002

When a power system experiences a serious disturbance on insufficient power, the system frequency may drop. For system frequency will be maintain standard value, under_frequency relay will reconstruct balance of power and load by load shedding. Currently load shedding scheme is due to establishment plan by fixed scenario. Where compare current scheme with past scheme, system frequency should be recovered by load shedding using rate of frequency decline. This paper suggests the dynamic load shedding scheme by using the rate of change of frequency when The Korea Electric power system is happened the large disturbance.

• Journal of the Optical Society of Korea
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• v.11 no.3
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• pp.124-129
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• 2007

For the first time we compare two kinds of optical frequency combs, one of which is based on a Ti:sapphire femtosecond laser and the other is based on a mode-locked erbium-doped fiber laser. The comparison is performed by measuring an optical frequency standard with these two combs simultaneously. The two frequency measurements agree within 1.8 Hz ($3.8{\times}10^{-15}$) with the uncertainty of 17.2 Hz ($3.6{\times}10^{-14}$), from which it can be concluded that the Ti:sapphire-based frequency comb and the fiber-based frequency comb have no systematic discrepancy at this level of uncertainty.

• Journal of Korean Clinical Health Science
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• v.1 no.3
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• pp.1-9
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• 2013

Purpose. This research is implemented to identify the status of educations about the pricing standard, status of the cognition of the pricing standard, and the solutions to the questions on the pricing standard of the oral health professionals. it will provide the easier accessibility to the annual changes in Dental Health Insurance Standards to the oral health professionals. Methods. The research subjects are the total 204 oral health professionals in limited area, and it was analyzed with structured questionnaires. The collected data is analyzed by IBM SPSS ver. 19.0, a statistical program (IBM Co., Armonk, NY, USA) for the frequency and percentage, and ANOVA. The result is as following Results. The awareness of dental health insurance standard was statistically significant differences by age (p<0.01), career (p<0.001), the prime task (p<0.01), and dental insurance claimants (p<0.05). The awareness of the standard was statistically significant differences by educational training within last 6 months (p<0.05), the cognition of the standard (p<0.001), and solutions for the questions (p<0.05). Conclusions. As the results of the research, it is necessary to develop the educational program under condition of age, career, main task, and better understanding in Dental Health Insurance Standard for oral health professional.

• Journal of the Optical Society of Korea
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• v.7 no.3
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• pp.131-134
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• 2003

We demonstrated an optical frequency synthesizer based on a femtosecond (fs) mode-locked Ti:sapphire (Ti:s) laser by simultaneously stabilizing the carrier-offset frequency, $f_{ceo}$, and repetition rate, $f_{ rep}$, referenced to the Cs atomic frequency standard. By using two wide-band digital phase-detectors we realized a phase-coherent link between $f_{rep} and f_{ceo} with the relation f_{ceo} = f_{AOM} 5/6f_{rep} ≡ 0, where f_{AOM} = 5/6f_{rep}$ is the phase-locked driving frequency of an acousto-optic modulator (AOM) in a self-referencing interferometer and $f_{rep}$ = 100 MHz. As a result, we could stabilize all components of the fs laser comb at once with an equal frequency separation $f_{rep}$ = 100 MHz with $f_{ceo}$ = 0. In our optical frequency synthesizer, the frequency of the nth component ($f_{n}$) is given exactly by the simple relation $f_n = nf_{rep}$, enabling us to use the fs laser comb as a frequency ruler in the optical frequency metrology.

• Tunnel and Underground Space
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• v.19 no.6
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• pp.490-497
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• 2009

The horizontal and vertical response spectra using the observed ground motion from the recent 5 macro earthquakes were analysed and then were compared to both the seismic design response spectra(Reg Guide 1.60), applied to the domestic nuclear power plants, and the Korean Standard Design Response Spectrum for general structures and buildings(1997). 74 horizontal and 89 vertical observed ground motions, without considering soil types, were used for normalization with respect to the peak acceleration value of each ground motion. The results showed that the horizontal MPOSD(Mean Plus One Sigma Standard Deviation) response spectra revealed much higher values for the whole frequency bands above 1 Hz than Reg. Guide(1.60). For the vertical response spectra, the results showed slightly higher than just between 7 and 8 Hz frequency band. The results were also compared to the Korean Standard Response Spectrum for the 3 different soil types and showed that the horizontal MPOSD response spectra revealed much higher values for the whole periods below 2 second(0.5 Hz) than those of SE soil type. The vertical response spectra showed similar to the values of the Korean Standard Response Spectrum of SD soil type. These spectral values dependent on frequency could be related to characteristics of the domestic crustal attenuation and the effect of each site amplification. However, through the qualitative improvements and quantitative enhancement of the observed ground motions, the conservation of horizontal seismic design response spectrum should be considered more significantly for the whole frequency bands above the 1 Hz.