• Annals of Clinical Neurophysiology
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• v.16 no.2
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• pp.49-54
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• 2014

Heart rate variability is significantly associated with cardiovascular complications in various neurological disorders with cardiac impairment. Measures of spontaneous heart rate variability might be different from provocating tests of heart rate variability such as deep breathing and Valsava maneuver. Methods for analysis are divided into time domain methods and frequency domain methods. There are standard deviation of NN interval, standard deviation of average NN interval, root mean square of the successive differences, NN50, and pNN50 in time domain methods. Frequency domain bands can be divided into very low, low, and high frequency. Each variables are influenced by sympathetic and/or parasympathetic activity.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.133-134
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• 2006

In this paper the platform system for IEEE 802.15.4 Low Rate WPAN is designed and fabricated. IEEE 802.15.4 Low Rate WPAN system serves the functions and realization of home-area network. According to the IEEE 802.15.4 standard, there are two modes, One is BPSK modulation in 868/915MHz frequency band. The other is O-QPSK modulation in 2.45GHz frequency band. In this paper we implemented the platform system mounted in one PCB board in 868/915MHz frequency band of IEEE 802.15.4 Low Rate WPAN system. We measured that the platform system which consists of digital part and RF part has good performance. Also RF part is realized by design and fabrication of the RF transceiver IC. The key issue is to make the platform system which provides the function of Low Rate WPAN system to meet the requirement of IEEE 802.15.4 standards.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.5
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• pp.647-654
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• 2005

Recently, the economic losses caused by inundation are increasing due to the urbanization and industrialization, i.e., intensive land utilization and concentration of population and properties. It is regarded that the role of the storm sewer systems in urban areas becomes more important as one of the effective countermeasures for reducing the inundation losses. In this study, the effects of rainfall design frequency enhancement on the construction cost of the storm sewer systems were analyzed by increasing the design frequency from the present design frequency of the sewer systems, which is 5~10 years, to 15 years, 20 years and 30 years. The change rate functions of the design discharge and construction cost based on the various design frequencies were derived by regression analysis. According to the analysis, change the rate of design discharge at 15, 20, 30 years rainfall design frequencies were increased by 10%, 17.1%, and 27.2%, respectively, when compared to that at 10 year frequency. Furthermore, it was found that by increasing the design frequency from 10 years to 15 years, 20 years and 30 years, the construction costs were increased by 5.0%, 8.0% and 12.4%, respectively. Finally, their reliabilities need to be tested by applying the rate functions to the real storm sewer districts.

• Journal of Power Electronics
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• v.19 no.4
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• pp.980-988
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• 2019

When compared with traditional power frequency generators, the frequency of a super high-speed permanent magnet generator (SHSPMG) is a lot higher. In order to study the influence of frequency on the electromagnetic field of SHSPMGs, a 60000rpm, 117kW SHSPMG was taken as a research object. The two-dimensional finite element model of the generator was established, and the two-dimensional transient field of the generator was simulated. In addition, a test platform of the generator was set up and tested. The reliability of the simulation was verified by comparing the experiment data with that of the simulation. Then the generator electromagnetic field under different frequencies was studied, and the influence mechanism of frequency on the generator electromagnetic field was revealed. The generator loss, voltage regulation rate, torque and torque ripple were analyzed under the rated active power load and different frequencies. The influences of frequency on the eddy current density, loss, voltage regulation rate and torque ripple of the generator were obtained. These conclusions can provide some reference for the design and optimization of SHSPMGs.

• CELLMED
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• v.5 no.1
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• pp.4.1-4.4
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• 2015

Yoga is an ancient Indian system of life, encompassing various practices including practices for self-discipline and also for regulating the health states of the individual, being practiced for thousands of years. The present study aims at understanding the effect of two high frequency breathing practices over autonomic nervous system. Forty healthy male volunteers of age $21{\pm}2$ years with $9{\pm}3$ months of Yoga practice experience were recruited. The two high frequency Yoga breathing practices, kapalabhati (KB) and bhastrika (BH) were given as interventions randomly on either of the two days to minimise laboratory bias. They were assessed before and immediately after the interventions for heart rate, respiratory rate, heart rate variability (HRV), blood pressure and peripheral oxygen saturation. There was a significant increase in heart rate (p<0.01; p<0.001), systolic blood pressure (p<0.01; p<0.001), NN50 (p<0.01; p<0.001) component of HRV for both KB and BH groups respectively. There was a significant reduction in respiratory rate in both the groups (p<0.001, and p<0.05, BH and KB respectively) immediately following intervention. A significant increase in LF component of HRV and reduction in Diastolic blood pressure and high frequency (HF)component following KB was also observed (p<0.05, for all comparisons). The Mean peripheral oxygen saturation remained unaltered in both the groups (p>0.05).The results suggest that high frequency yoga breathing practices induce physiological arousal immediately as evidenced by increased blood pressure and heart rate. The sympathetic arousal was more following KB session as evidenced by an increased diastolic blood pressure, LF power and a decrease in HF power of HRV as compared to the BH session.

• Safety and Health at Work
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• v.11 no.3
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• pp.266-274
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• 2020

Background: From only frequency rate of industrial accidents, it is difficult to define the industry composition of accident statistics in a nation. This study aims to propose and develop a new index for measuring the degree of concentration of industrial accidents using the concept of the Herfindahl-Hirschman Index in the case of European countries. Methods: Using the concept of the Herfindahl-Hirschman Index, the concentration index of accidents in the country is developed, and the conditions of European countries are compared using indexes of frequency rate and concentration ratio. Results: The frequency rate and concentration ratio of fatal and nonfatal accidents in European countries are compared. According to the economic condition and geographical position, different patterns of accidents concentration are presented in terms of frequency rate and concentration ratio. Conclusion: We develop the concentration index of industrial and occupational accidents that identifies the industrial ratio of accident occurrence, and the differentiated strategy can be formulated such as approaches to reducing frequency and prioritizing target industries.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.2
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• pp.223-228
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• 2007

The Digital Frequency Synthesizer(DFS) that generates the wideband signal with high speed frequency hopping rate and high frequency resolution characteristics was designed and implemented in this paper The DFS was applied as local oscillator for direct frequency conversion IF modules of DVB-RCS, which directly generates the transmission immediate frequency signal by using DDS and wideband PLL technologies. The DDS technology provides high speed frequency hopping rate and high frequency resolution characteristics, which are also the DVB-RCS requirement. The wideband PLL technology also provides the wideband signal generation, which is a necessity for direct frequency conversion modules. The implemented DFS provides the spurious suppression characteristic of -50 dBc and less, frequency resolution of 0.233 Hz and frequency hopping rate of 125 ns, respectively. Also the DFS represents the amplitude flatness of 3 dB and less in the pass-band, and phase noise characteristic of -75 dBc/Hz at 1 kHz frequency offset.

• Journal of the Korean Society of School Health
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• v.5 no.1
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• pp.101-110
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• 1992

We investigated each 50 students in the primary school its 1st year student(boys & girls) on the conditions of oral hygiene between urban and rural children centering around the dental caries. The purpose of this study is to promote national oral health and to offer the basic data on the oral health level of community. We got conclusion as follows : 1. Sex : The prevalence rate of dental caries between the rural and urban children showed high to the urban children. 2. Education Level of Parents : When the educational background of father is high, the prevalence rate of dental caries showed high(P<0.01). The educational background of mother has not influenced on the prevalence rate. 3. Economic Level of Home : When the economic level of home is high, the prevalence rate of dental caries is high(P<0.01). 4. Intake Frequency of Eating Between Meals : The average intake frequency of eating between meals a day of urban children was $2.3{\pm}0.76times$, the average intake frequency of eating between males a day of urban children was $2.79{\pm}0.82times$(P<0.01). 5. Brushing Frequency : The average brushing a day of rural children was $2.48{\pm}0.82times$, urban children was $2.34{\pm}0.71times$, and when the brushing frequency is high, the prevalence rate of dental caries showed low(P<0.01). 6. Brushing Time : The rural children and urban children had no difference, but brushing time had influenced on the prevalence rate(P<0.01). 7. Kinds of Drinking Water: The kinds of drinking water had not influenced on the prevalence rate of dental caries. 8. Amount of Pocket Money : The urban children is the more amount of pocket money than the rural, when the amount of pocket money is lots, the prevalence rate of dental caries showed high(P<0.01). 9. Average Intake Frequency a day for the caries food of eating between meals of rural children was 2.91 times and urban children was 3.47 times. The average intake frequency a day for the caries food of eating between meals had influenced on the prevalence rate dental caries. In the point of view for the oral health, the urban children is bad than the rural children in the actual conditions of intake. The education of oral health for parents has demanded, the necessity of oral control for the children of the improvement effectively as the methods to maintain the oral health level.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.215-217
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• 2008

The most widely used method for searching contents of mot ion picture compares contents by extracted cuts. The cut extract ion methods, such as CHD(Color Histogram Difference) or ECR(Edge Change Ratio), are very weak at modifications such as cropping, resizing and low bit rate. The suggested method uses audio contents for indexing and searching to make search be robust against these modification. Scenes of audio contents are extracted for modification-robust search. And based on these scenes, make spectral powers binary on each frequency bin. in the time-frequency domain. The suggested method shows failure rate less than 1% on the false positive error and the true negative error to the modified(using cropping, clipping, row bit rate, addtive frame) contents.

• Journal of Biomedical Engineering Research
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• v.39 no.1
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• pp.16-21
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• 2018

In this study, we investigated the activity of Mirror Neuron System(MNS) and Steady State Visual Evoked Potential(SSVEP) according to frequency and duty rate of the flickering action video. Eight subjects were recruited for this study. The stimulus was consisted of a three-minute black and a flickering action video and they were repeatedly presented every six seconds. We used 50%, 75% of duty rate for each frequency 7.5 Hz and 15 Hz, and we also used the non-flickering condition and rest condition. As a result, the Mu suppression was the largest at 7. 5Hz and 50% duty rate and the SSVEP power was higher at 15 Hz than 7.5 Hz.