• Economic and Environmental Geology
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• v.20 no.4
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• pp.247-260
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• 1987

As a part of study on the structure of the Yangsan Fault, geological and VLF EM studies have been made in the fault area approximately between Kyeongju and Eonyang. The result provides comparatively clear information on the trace of the fault and extent of fracture zone as well as the structural characteristics of the Yangsan Fault area. The location of fault trace identified from this VLF EM study coincides well in general with that expected from geological information of the area. And the extent of fault fracture zone turn out to be characterized by U shaped low resistivity zone whose width increases from north to south.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.16 no.3
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• pp.49-58
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• 2012

Objectives: This research was designed to study the characteristics of heart rate variability in acute dyspepsia patients compared with normal group. Methods: The testing of HRV was carried out at Oriental Medical Center of ${\bigcirc}{\bigcirc}$University with the participation of 94 acute dyspepsia patients and 85 control group people. We checked HRV of the 2 groups that were checked on the first visit day and compared HRV index between groups. Results: In the frequency domain analysis, HF, LF, VLF, LF/HF ratio, TP were significantly lower than control group on acute dyspepsia patient group. HF, LF, VLF, LF/HF ratio, TP were not significantly associated with age. Conclusions: According to this study, autonomic nerve system was more decreased on the acute dyspepsia patient group compared with the control group. Though further studies will be needed, the present finding provide us the possibility that stress is a major cause of the acute dyspepsia along with food factor.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.2
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• pp.142-153
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• 2008

Objective : Etiologically, stress is a important factor to immune system and skin disease. Human body is controled to keep his homeostasis from stress by autonomic nerve system. So we investigated autonomic nerve balance and stress level of patients with skin disease by heart rate variability(HRV) test. Research Methods and Procedures : Fifty two patient(from 15 years old to 35 years old) who visited Dept. of Oriental medical Dermatology, Kyunghee university at first and had an examination by HRV test, were selected as the subject of our study. We checked items of HRV test(such as SDNN, RMSSD, VLF, LF, HF, TP, norm-LF, norm-HF, LF/HF ratio, LnHF and LnHF), and analyzed time and frequency domain by sex, age, onset, color on end of patient's tongue, sweating and sleep condition. Results and Conclusion : Men showed significant higher SDNN, RMSSD, LF, norm-LF, norm-HF, LF/HF ratio, LnLF and LnHF than women(p <0.05). Patients who were attacked by skin disease within 6 months, showed significant higher TP and VLF than over 6 months(p <0.05). Patients with normal color on the end of their tongue showed significant higher TP and VLF than with flare color. We analyzed correlation to color on the end of tongue and RMSSD. Prevalence risk(RMSSD <20ms) in the case of normal color on the end of tongue was 5 times as high as in the case of flare color(p <0.1). And we analyzed correlation to age and LF/HF ratio. Prevalence risk(LF/HF ratio <1) of patients from 15 years old to 25 years old was 1.467 times as high as from 26 years old to 35 years old(p <0.1).

• The Journal of Engineering Geology
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• v.9 no.1
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• pp.45-57
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• 1999

Groundwater flow in rock mass is controlled by the fractures developed in the area. So, the conductive fractures are very important for groundwater flow in crystalline rock. This study aims to find out the characteristics of the fracture distributed in granitic rock in the northern part of the Yusong area (latitude $36^{\circ}24'18"~36^{\circ}25'08",{\;}longitude{\;}127^{\circ}21'00"~127^{\circ}23'23"$). The electric and EM surveys were carried out in the site to delineate the fracture the fracture zones. Since geophysical survey provides non-unique solution, hydraulic data and dilling log data including BHTV scanning were used as complementary data to achieve the objective of this study. Electric survey(DC) arrays used are schlumberger and dipole-dipole arrays. VLF is used for EM survey. The main charcteristics of the fracture developed in the study aera are that fractures associated with basic dyke cut corss the main fracture zone in NNW and play an important role as hydraulic barrier. In trun, groundwater table in the upstream area is lower than that downstream area.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.207-212
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• 2015

Continuous, high-quality supply of electrical energy is the backbone of any modern economy. Any equipment operating at a power station must be reliable and safe. All major power supply components such as transformers, cables, generators, and switchgear need to be kept in perfect operating condition. The lifetime of power cables, used as the main means of transferring electric power, is understood to be about 30 years, from the time of manufacturing. The dielectrics between two conductors of a cable must be able to withstand electrical stresses from high-voltage input. This condition should be verified throughout the lifetime of the cable system. Several techniques, such as VLF-tan${\delta}$, partial discharge, and insulation resistance are used in order to determine the operating conditions of cables. In this paper, we present our work on insulation resistance to diagnose cables in operation at the Western Power station in Taean, Chungcheong Namdo Province, South Korea. As a result we have found cables the life time of which is 38 years.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1616-1626
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• 2010

This paper will show how self-alarming EAS(Electronic Article Surveillance) system can improve its receiving performance of magnetic field signal and reduce false alarm using dual-band wireless communication. Our research improved the receiving performance and the areas of recognition of magnetic signal through the change of VLF receiving circuit and alarm transmitting method. In addition, we verified the reduction of false alarm by improvement of integrity and distance between tag and receiver through experiment. Thanks to our research, we can build the high performance and economical EAS with low false alarm on the multi gate store.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.6
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• pp.37-46
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• 2015

The wireless electrocardiographic monitoring system(WDMS) is designed to be long term monitoring for the early detection of cardiac disorders. The current version of the WDMS can identify two types of cardiac rhythms in real-time, such as atrial fibrillation(AF) and normal sinus rhythm(NSR), which are very important to track cardiac-rhythm disorders. In this study, we proposed the analysis method to discriminate the characteristics statistically evaluated in both time and frequency domains between AF and NSR using various parameters in the heart rate variability(HRV). And we applied various ECG detection methods (e.g., difference operation method) and compared the results with those of the discrete wavelet transform(DWT) method. From the statistically results, we found that the parameters such as STD RR, STD HR, RMSSD, NN50, pNN50, RR Trian, and TNN(p<0.05) are significantly different between the AF and NSR patients in time domain. On the other hand, the frequency domain analysis results showed a significant difference in VLF power($ms^2$), LF power($ms^2$), HF power($ms^2$), VLF(%), LF(%), and HF(%). In particular, the parameters such as STD RR, RMSSD, NN50, pNN50, VLF power, LF power and HF power were considered as the most useful parameters in both AF and NSR patient groups. Our proposed method can be efficiently applied to early detection of abnormal conditions and prevent the such abnormals from becoming serious.

• Economic and Environmental Geology
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• v.31 no.1
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• pp.59-68
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• 1998

Gravity, magnetic and VLF surveys were carried out to investigate the dimension, nature and stability of the waste materials filled in the Seokdae landfill, Pusan. The Seokdae landfill, which is located in a former valley, was used as a dump for mainly domestic-type waste materials for 6 years from 1987. The landfill site is classfied into A, B, C and D areas according to the sequence of dumping period. The Bouguer gravity anomaly map shows maximum variation of 3.1 mgals on the landfill and its general appearance has close relation with the thickness of waste filled. The local variation of anomaly, however, reflect the degree of compactness of waste materials which may be affected by the nature of waste and dumping time. In the case of area A, where dumping process was terminated at the very last stage, most part show negative anomaly compared to other areas. We think that the composition of the waste materials in the area A is high in leftover food and paper trash and they are still in uncompacted condition. In area B, the general trend of variation of gravity anomaly is appeared to be high anomaly in northern part and decrease to the southern part. This is well matched with the prelandfill topography of the landfill site. The southern part of area B is located in the center of valley and its present surface is comparatively rugged, which may be due to the differential settlement of deep burried waste. The thickness of waste in area C is relatively thin, but the gravity anomaly appears to be low. Considering the present condition of surface, it can be inferred that low density wastes such as leftover food were mainly filled in this area. Area D, as in the case of area B, shows gravity anomaly that has close relation with the prelandfill topography. Magnetic data show the variation of total field intensity varies in the range of 46600~51000 nT, and reach maximum anomaly of 4400 nT. The overall pattern of magnetic anomaly well reflects the distribution of magnetic materials in the landfill. The result of VLF survey reveals several low resistivity zones, which may serve as underground passages for contaminant flow, in the area C located near the small Village.

• Journal of Naturopathy
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• v.11 no.1
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• pp.1-8
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• 2022

Background: A validation study is needed to make domestic applications of German Kneipp therapy. Purpose: The study aims to test the effect of a Kneipp therapeutic program in a domestic forest environment on the autonomic nervous system. Methods: The program was made considering the 4 key elements ('exercise', 'regulative therapy', 'nutrition', and 'phytotherapy') of the Kneipp therapy. Total 3 sessions (once a week for 5 hours in each session) were performed to 40 domestic adults divided into four groups (10 in each group). HRV was measured on the subjects before and after the intervention, and its 6 characteristic parameters (TP, VLF, LF, HF, LF/HF, CSI: Cumulative Stress Index) were compared for statistical analysis. Results: For 33 subjects excluding 7 who were disturbed by interrupt factors during measurements, significant improvements after the intervention, were observed in TP(8.64%, p < ..001), VLF(6.96%, p < .05), LF(15.86%, p < .001), HF(8.46%, p < .01), LF/HF(5.77%, p < .05) and CSI(-16.06%, p < ..001). Conclusions: The Kneipp therapy performed in the forest environment was shown to activate the autonomic nervous system and in particular the sympathetic and parasympatheric nervous to promote heart activity, and was also shown to most significantly reduce cumulative stress. The present observations would be the first preliminary evidence that the Kneipp therapeutic interventation in a domestic forest environment results in positive responses of the autonomic nervous system including stress relief.

• Journal of Naturopathy
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• v.9 no.1
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• pp.27-32
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• 2020

Purpose: The purpose of this study was to investigate the changes in the autonomic nervous system of the human body after the use of ocher bedding radiating far-infrared rays to 15 insomnia subjects. Methods: Changes of autonomous nerve in the subjects after using loess bedding estimated by heart rate variability. Results: The mean HF before the use of ocher bedding was 220.8 msec², and the mean after use decreased to 5.1 msec². The average value of LF before use was 418.1 msec², and the mean after use decreased to 5.2 msec². The average before use of the VLF was 1463.3 msec², and the average after use dropped to 6.8 msec². The average value of TP before use was 977.3 msec², and the average after use dropped to 6.7 msec². The decrease in postoperative values of all four items was statistically significant, and the high value of the subjects before use inferred to be the reason that all of the subjects had high stress and anxiety due to their long-term sleep disorder. There was no significant difference in the pulses of the subjects before the use of the bedding. SDNN and RMSSD were not significantly different before and after use. Conclusions: Autonomic nerves HF, LF, VLF, TP frequency is evaluated to be affected by the investigation of far-infrared radiation that occurs ocher. This research data regarded as high value as primary data in this field.