• Journal of Korean Traditional Oncology
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• v.16 no.1
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• pp.15-31
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• 2011

Objective : The study aims to investigate the effect of moxibustion treatments on autonomic nervous system function of cancer patients through the evaluation of heart rate variability (HRV) biofeedback testing. Materials and Methods : Six cancer patients from inpatient care unit of Dunsan Oriental Hospital, Daejeon University were given three moxibustion treatment sessions every other day over one week period on five Oriental Medicine meridian points CV4, CV6, CV12, KD1, and PC8. HRV biofeedback was conducted before and after each treatment sessions. Three areas of analyses were done from the test conducted; Time Domain Analysis, Frequency Domain Analysis and Autonomic Nervous System (ANS) balance analysis. Results : Time Domain Analysis has shown increased Standard Deviation of all Normal R-R Intervals (SDNN), and decreased Mean Heart Rate and Physical Stress Index (PSI) levels, with statistical significance (P<0.05). In Frequency Domain Analysis, series of moxa treatments have increased Total Power (TP), Very Low Frequency Oscillation Power (VLF), High Frequency Oscillation Power (HF), normalized HF values while decreasing Low Frequency Oscillation Power (LF), normalized LF and LF/HF ratio with statistical significance (P<0.05). The values of ANS activity, ANS balance, Stress resistance, Stress index, have also shown significant changes. For cardiac stability stroke volume power (SP) and Blood Vessel Tension (BVT) were followed, which were both increased after treatment. All changes were statistically significant (P<0.05). Conclusion : The results have shown a positive correlation between the moxibustion treatments and autonomic nervous system responses on cancer patients through the HRV biofeedback testing. This study suggests possible application of moxibustion treatments for managing ANS functions of cancer patients, although additional studies with larger population are necessary to confirm the data.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.727-732
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• 2020

In this paper, when a refractive index grating and a gain grating were simultaneously present in a DFB laser having a wavelength of 1.55 ㎛, a dielectric film coating was applied so that reflection did not occur on the right mirror surface, so that 𝜌_r=0. In case of δL > 0, the threshold gain and the beam distribution in the longitudinal direction and the radiated power ratio P_l/P_r of the oscillation mode were compared for the cases of the phase of 𝜌_l=π and π/2. If the phase of 𝜌_l=π, in order to obtain a low threshold current and high frequency stability, κL should be greater than 8. In the case of the phase of 𝜌_l= π/2, when κL is larger than 4.0, the oscillation gain starts to be lower than when the phase of 𝜌_l=π. In order to lower the threshold current of a oscillation mode and enhance the frequency stability, κL should be greater than 8.

• Journal of the Korean earth science society
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• v.29 no.5
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• pp.375-385
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• 2008

The relationship between two interannual climate variabilities and the frequency of tropical cyclone (TC) that landed over the Korean Peninsula (KP) has investigated for the period of 1951-2004. In the analysis of the relationship between KP-landfall TC frequency and the ENSO phase, most TCs of C-14 (TCs that do not pass through mainland China before landing the KP) and C-23 (TCs that pass through mainland China before landing the KP) tended to more land in the warm phase than normal and cold phases. However, TC intensity at landfall was stronger in the cold and normal phases. In the analysis of the relationship between KP-landfall TC frequency and Arctic Oscillation (AO) phase, the TCs of C-14 tended to more land in the positive (POS) phase of AO and the negative (NEG) phase of AO for C-23. It was found that AO index was negatively correlated with the Ni$\tilde{n}$o-3.4 index. And then the TCs of C-14 landed more frequently over the KP in the AO POS - Ni$\tilde{n}$o-3.4 NEG phases and in the AO NEG - Ni$\tilde{n}$o-3.4 POS phases for the TCs of C-23.

• Journal of the Korean earth science society
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• v.40 no.6
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• pp.561-571
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• 2019

To understand the genesis of tropical cyclones (TC), we computed TC genesis probability (GPr) by partitioning a highly localized genesis frequency (GFq) into nearby grid boxes in proportion to the spatial coherence of genesis potential index (GPI). From the analysis of TCs simulated by the Seoul National University Atmosphere Model Version 0 and the observed TCs, it was shown that GPr reasonably converges to GFq when averaged over a long-term period in a decent grid size, supporting its validity as a proxy representing a true TC GPr. The composite anomalies of the gridded GPr in association with the Asia summer monsoon, El Nino-Southern Oscillation (ENSO), and the Madden-Julian Oscillation (MJO) are much less noisy than those of GFq, and consequently are better interpretable. In summary, GPr converges to GFq, varies more smoothly than GFq, represents the spatiotemporal variations of GFq better than GPI, and depicts GFq with greater spatial details than other spatially smoothed GFqs.

• Journal of Korea Water Resources Association
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• v.51 no.12
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• pp.1247-1260
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• 2018

This study investigated the effect of arctic oscillation by analyzing the cross-correlation characteristics between the arctic oscillation index (AOI) and the number of typhoons occurred in the North Pacific, the number of typhoons affecting South Korea, total rainfall amount and number of rainy days during the monsoon season in South Korea. For this analysis, the monthly AOI data were transformed into the average data about January and seasonal AOI data representing winter, spring, fall and winter. The typhoon data and monsoon data were all those collected annually. The data period for this analysis was determined to be from 1961 to 2016 by considering the data available. Based on this analysis, it was found that the arctic oscillation has a weak but statistically significant effect on the monsoon characteristics of South Korea. However, the level of effect was not consistent over the data period but varied significantly periodically. For example, the cross-correlation coefficient derived for the recent 10 years was estimated to be higher than 0.8, but was simply insignificant during the 30 years before the last decade. The overall effect of arctic oscillation on the occurrence of typhoon was found to be statistically insignificant, but was also fluctuating periodically to show somewhat significant effect. Finally, it should be mentioned that the effect of arctic oscillation on the typhoon and monsoon had been changing by turns from 1960s to 2000s. However, in the 2010s, it happened that the effect of arctic oscillation has become significant on both typhoon and monsoon in South Korea.

• Journal of the Korean earth science society
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• v.33 no.7
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• pp.583-595
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• 2012

The potential for tropical cyclogenesis in a given oceanic and atmospheric environments can be represented by genesis potential index (GPI). Using the 18 Coupled Model Inter Comparison Project phase 5 (CMIP5) models, the annual cycle of GPI and interannual variability of GPI are analyzed in this study. In comparison, the annual cycle of GPI calculated from reanalysis data is revisited. In particular, GPI differences between CMIP5 models and reanalysis data are compared, and the possible reasons for the GPI differences are discussed. ENSO (El Nino and Southern Oscillation) has a tropical phenomenon, which affects tropical cyclone genesis and its passages. Some dynamical interpretations of tropical cyclogenesis are suggested by using the fact that GPI is a function of four large-scale parameters. The GPI anomalies in El Nino or La Nina years are discussed and the most contributable factors are identified in this study. In addition, possible dynamics of tropical cyclogenesis in the Northern Hemisphere Pacific region are discussed using the large-scale factors.

• Ocean and Polar Research
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• v.40 no.3
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• pp.127-143
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• 2018

This study analyzed the influence of climate change on the spawning ground area of the common squid, Todarodes pacificus. To estimate long term changes in the area of the spawning ground of the common squid, water temperature at 50 m deep that can be inferred from sea surface temperature (SST) based on both NOAA/AVHRR (1981.07-2002.12) and MODIS/AQUA (2003.01-2009.12) ocean color data was analyzed. In addition, five climate indices, Arctic Oscillation Index (AO), Siberian High Index (SH), Aleutian Low Pressure Index (ALP), East Asia Winter Monsoon Index (EAWM) and Pacific Decadal Oscillation (PDO) which are the main indicators of climate changes in the northwestern Pacific were used to study the relationship between the magnitude of the estimated spawning ground and climate indices. The area of the estimated spawning ground was highly correlated with the total catch of common squid throughout four decades. The area of the estimated spawning ground was negatively correlated with SH and EAWM. Especially, PDO was negatively correlated with the area of the spawning ground in the northwestern Pacific (r = -0.39) and in the southern part of the East Sea (r = -0.38). There was a positive relationship between the AO and the area of the spawning ground in the northwestern Pacific (r = 0.46) as well as in the southern part of the East Sea (r = 0.32). Temporally, the area of the winter spawning ground in the southern part of the East Sea in the 1980s was smaller than those areas in the 1990s and 2000s, because the area was disconnected with the western coastal spawning ground of Japan in the 1980s, while the area had been made wider and more continuous from the Korea strait to the western coastal water of Honshu in the 1990s and 2000s.

• Journal of Power Electronics
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• v.14 no.3
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• pp.531-540
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• 2014

A novel carrier-based PWM (CBPWM) strategy of a three-level NPC converter is proposed in this paper. The novel strategy can eliminate the low-frequency neutral point (NP) voltage oscillation under the entire modulation index and full power factor. The basic principle of the novel strategy is introduced. The internal modulation wave relationship between the novel CBPWM strategy and traditional SPWM strategy is also studied. All 64 modulation wave solutions of the CBPWM strategy are derived. Furthermore, the proposed CBPWM strategy is compared with traditional SPWM strategy regarding the output phase voltage THD characteristics, DC voltage utilization ratio, and device switching losses. Comparison results show that the proposed strategy does not cause NP voltage oscillation. As a result, no low-frequency harmonics occur on output line-to-line voltage and phase current. The novel strategy also has higher DC voltage utilization ratio (15.47% higher than that of SPWM strategy), whereas it causes larger device switching losses (4/3 times of SPWM strategy). The effectiveness of the proposed modulation strategy is verified by simulation and experiment results.

• Structural Engineering and Mechanics
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• v.82 no.4
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• pp.517-542
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• 2022

The effect of mean angle of wind attack on the flutter critical wind speed of two generic bridge deck cross-sections, viz, one closed box type streamlined section (deck-1) and closed box trapezoidal bluff type section with extended flanges/overhangs (deck-2) type of section have been studied using Computational Fluid Dynamics (CFD) based forced vibration simulation method. Owing to the importance of the effect of the amplitude of forcing oscillation on the flutter onset, its effect on the flutter derivatives and flutter onset have been studied, especially at non-zero mean angles of wind attack. The flutter derivatives obtained have been used to evaluate flutter critical wind speeds and flutter index of the deck sections at non-zero mean angles of wind attack studied and the same have been validated with those based on experimental results reported in literature. The value of amplitude of forcing oscillation in torsional degree of freedom for CFD based simulations is suggested to be in the range of 0.5° to 2°, especially for bluff bridge deck sections. Early onset of flutter from numerical simulations, thereby conservative estimate of occurrence of instability has been observed from numerical simulations in case of bluff bridge deck section. The study aids in gaining confidence and the extent of applicability of CFD during early stages of bridge design, especially towards carrying out studies on mean incident wind effects.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.124-133
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• 2004

Global climate variations are expected to affect local hydro-meteorological variables like precipitation and temperature. The Southern Oscillation (SO) is one of the major driving forces that give impact on regional and local climatic variation. The relationships between SO and local climate variation are, however, characterized by strong nonlinear variation patterns. In this paper, the nonlinear dynamic relationship between the Southern Oscillation Index (SOI), precipitation, and temperature in Fukuoka, Japan, is investigated using by a nonlinear multivariable approach. This approach is based on the joint variation of these variables in the phase space. The joint phase-space variation of SOI, precipitation, and temperature is studied with the primary objective to obtain a better understanding of the dynamical evolution of local hydro-meteorological variables affected by global atmospheric-oceanic phenomena.