• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2002년도 춘계학술대회 논문집
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• pp.314-319
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• 2002

To inspect how the different sensitivities in BAS (or BIS) moderate on the HRV pattern stimulated by positive or negative affective sound, we measured the electrocardiogram (ECG) of 25 students, consisted of 4 groups depending on the BAS (or BIS) sensitivity, while listening music or being exposed to noise. The power spectral density of HRV was derived from the ECG, and the power of HRV was calculated for 3 major frequency ranges (low frequency [LF], medium frequency [MF], and high frequency [HF]). We found that the index MF/(LF+HF), while listening music, was 20 % higher in the individuals with a low BIS but high BAS than in the individuals with a low sensitivity In both BIS and BAS. Moreover, in the former group this index was 30 % higher while listening music than while being exposed to noise. From these results we suggest that individuals with a low BIS but high BAS be more sensitive to positive affective stimuli than other groups, and the index MF/(LF+HF) be applicable to evaluate positive affects.

• The Korean Journal of Pain
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• 제22권1호
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• pp.39-46
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• 2009

Background: Ketamine has an indirect sympathetic stimulation effect. We investigated heart rate variability (HRV) as a marker of cardiac autonomic function after a target controlled infusion (TCI) of ketamine with a plasma concentration of 30 or 60 ng/ml. Methods: In 20 adult volunteers, the mean of the R wave to the adjacent R wave interval (RRI), the range of RRI, the root mean square successive difference of intervals (RMSSD), the total power, the low frequency (LF, 0.04-0.15 Hz) power, the high frequency (HF, 0.15-0.4 Hz) power, the normal unit HF (nuHF), the normal unit LF (nuLF), the LF/HF ratio and the SD1 and the SD2 in the Poincare plot were measured before and after a TCI of ketamine. We observed for any psychedelic symptoms or sedation. Results: There were no differences in the mean and range of the RRI, RMSSD, total power, LF power, HF power, nuHF, nuLF, LF/HF ratio, SD1 and SD2 between before and after ketamine administration. The OAA/S score was higher and there were more psychedelic symptoms with a 60 ng/ml plasma concentration than with a 30 ng/ml plasma concentration. Conclusions: This study did not show any effect of a low plasma concentration of ketamine on the autonomic nervous system.

• 대한의용생체공학회:의공학회지
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• 제42권1호
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• pp.25-30
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• 2021

Objective: The aim of this study is to consider the effect of skin tissue necrosis by improving blood flow in animal skin models for low frequency pulsed electromagnetic fields (LF_PEMF) stimulation. Methods: Twenty rats (Wistar EPM-1 male, 280-320 g) were randomly divided into control groups (n=10) and the PEMF groups (n=10). To induce necrosis of the skin tissue, skin flap was treated in the back of the rat, followed by isolation film and skin flap suturing. Subsequently, the degree of necrosis of the skin tissue was observed for 7 days. The control group did not perform any stimulation after the procedure. For the PEMF group, LF_PEMF (1 Hz, 10 mT) was stimulated in the skin flap area, for 30 minutes a day and 7 days. Cross-polarization images were acquired at the site and skin tissue necrosis patterns were analyzed. Results: In the control group, skin tissue necrosis progressed rapidly over time. In the PEMF group, skin tissue necrosis was slower than the control group. In particular, no further skin tissue necrosis progress on the day 6. Over time, a statistically significant difference from the continuous necrosis progression pattern in the control group was identified (p<0.05). Conclusions: It was confirmed that low frequency pulsed electromagnetic fields (LF_PEMF) stimulation can induce relaxation of skin tissue necrosis.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권8호
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• pp.2068-2082
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• 2023

With the rapid development of deep learning, Depth Map Super-Resolution (DMSR) method has achieved more advanced performances. However, when the upsampling rate is very large, it is difficult to capture the structural consistency between color features and depth features by these DMSR methods. Therefore, we propose a color-image guided DMSR method based on iterative depth feature enhancement. Considering the feature difference between high-quality color features and low-quality depth features, we propose to decompose the depth features into High-Frequency (HF) and Low-Frequency (LF) components. Due to structural homogeneity of depth HF components and HF color features, only HF color features are used to enhance the depth HF features without using the LF color features. Before the HF and LF depth feature decomposition, the LF component of the previous depth decomposition and the updated HF component are combined together. After decomposing and reorganizing recursively-updated features, we combine all the depth LF features with the final updated depth HF features to obtain the enhanced-depth features. Next, the enhanced-depth features are input into the multistage depth map fusion reconstruction block, in which the cross enhancement module is introduced into the reconstruction block to fully mine the spatial correlation of depth map by interleaving various features between different convolution groups. Experimental results can show that the two objective assessments of root mean square error and mean absolute deviation of the proposed method are superior to those of many latest DMSR methods.

• The Korean Journal of Physiology and Pharmacology
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• 제3권6호
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• pp.605-613
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• 1999

The purpose of the present study was to evaluate cardiovascular regulation during passive standing (PS) after ethanol ingestion by spectral analysis of heart rate variability (HRV) in flushed and nonflushed subjects. Of 24 young male subjects, 8 belonged to flushed group (F) and 16 to nonflushed group (NF). Two sessions of 10-min PS were performed before and after ethanol (0.5 g/kg) ingestion. Powers of R-R interval variability in very low frequency $(VLF,\;0{\sim}0.05\;Hz),$ low frequency $(LF,\;0.05{\sim}0.15\;Hz)$ and high frequency $(HF,\;0.15{\sim}0.50\;Hz)$ bands, normalized powers (LFn and HFn) and LF/HF ratio were obtained. After ethanol ingestion, F showed higher heart rate than NF. PS increased LFn $(+22.9{\pm}3.6\;in\;NF,\;+12.8{\pm}4.7$ in F, in normalized units) and LF/HF $(+3.10{\pm}0.57\;in\;NF,\;+3.00{\pm}1.08\;in\;F)$ and decreased HFn powers. Ethanol ingestion increased LFn and LF/HF and decreased HFn. PS after ethanol resulted in higher LFn and LF/HF and lower HFn than the prior PS. F showed a greater and more sustained HRV change than NF after ethanol. In conclusion, PS or ethanol ingestion increased LFn and LF/HF and decreased HFn. Flushed subjects showed an accentuated HRV response to ethanol.

• 동의신경정신과학회지
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• 제13권1호
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• pp.19-37
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• 2002

Objectives : This study sought to define autonomic functional difference on heart rate variability between headache patients and normal subjects Methods : We determined, heart rate variability of 52 headache patients and 30 normal subjects by means of three time domain measures: Mean PR(mean pulse rate), SDNN(standard deviation of all normal R-R intervals), RMSSD(the square root of the mean of sum of the squares of differences between adjacent normal R-R intervals), and five frequency domain measures: TP(total power), VLF(very low frequency), LF(low frequency), HF(high frequency). Results : 1) RMSSD, TP, HF, HF Norm of HRV decreased with aging and LF Norm, LF/HF increased with aging in headache patients. 2) There was no significant differences between migraine and tention headache in any standard index of HRV, whereas, HRV of total headache patients were smaller than those of normal subjects. 3) In the gender comparison, SDNN, RMSSD, HF of tention headache patients were the smallest and then migraine patients, normal subjects in order with man, whereas, LF Norm, LF/HF of normal subjects were the smallest with man. RMSSD of migraine patients were the smallest and then tention headache patients, normal subjects in order with women. 4) In the term of history of headache patients, SDNN, RMSSD were getting lower as long term. 5) There was no significant differences of HRV in physical symptom of headache patients. Conclusions : All of these results show that standard index of HRV of headache patients were significantly different with normal subjects.

• Annals of Rehabilitation Medicine
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• 제42권6호
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• pp.777-787
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• 2018

Objective To examine the long-term effects of the low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) combined with task-specific training on paretic hand function following subacute stroke. Methods Sixteen participants were randomly selected and grouped into two: the experimental group (real LF-rTMS) and the control group (sham LF-rTMS). All the 16 participants were then taken through a 1-hour task-specific training of the paretic hand. The corticospinal excitability (motor evoke potential [MEP] amplitude) of the non-lesioned hemisphere, and the paretic hand performance (Wolf Motor Function Test total movement time [WMFT-TMT]) were evaluated at baseline, after the LF-rTMS, immediately after task-specific training, 1 and 2 weeks after the training. Results Groups comparisons showed a significant difference in the MEP after LF-rTMS and after the training. Compared to the baseline, the MEP of the experimental group significantly decreased after LF-rTMS and after the training and that effect was maintained for 2 weeks. Group comparisons showed significant difference in WMFT-TMT after the training. Only in the experimental group, the WMFT-TMT of the can lifting item significantly reduced compared to the baseline and the effect was sustained for 2 weeks. Conclusion The results of this study established that the improvement in paretic hand after task-specific training was enhanced by LF-rTMS and it persisted for at least 2 weeks.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.561-564
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• 1998

This paper evaluated autonomic nervous system function in 23 patients with syncope and a positive tilt test result, 21 with a negative test result, and 19 healthy controls. Indexes of heart rate variability were measured during supine resting, immediately afte rtilt-up, standing rsting, immediately before syncope and immediately after tiltdown. There were no significant differences among the groups in any of the indexes of heart rate varability over the 24-hour holter recordings. In patients with a positive tilt result, tilting gaused a decrease in low-frequency (LF) immediately before syncope and incsrease in high-frequency (HF) bands immediately before. In patients with a negative tilt result, tilting caused a decrease in low-frequency (LF) immediately before syncope and decrease in high-frequency (HF) bands immediately before, different from positive tilt results. Our findings showed that patients with vasovagal syncope have no chronic differences from normal subjects in autonomic nervous system activity, but that these patients respond differently to the orthostatic stimulus.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2007년도 춘계학술발표회 초록집
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• pp.71-72
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• 2007

In this study, we investigated the fabrication of MLR (multi-layer resist) with a very thin diamond-like carbon (DLC) layer. ArF PR/$SiO_2$/DLC MLR structure was investigated and etching characteristics of the DLC layer was patterned using $SiO_2$ hard-mask by varying the process parameters such as different high-frequency/low-frequency combination ($f_{LF}/f_{HF}$), HF/LF power ratio ($P_{HF}/P_{LF}$), $O_2$ flow and $N_2$ flow rate in $O_2/N_2$/Ar plasmas. The results indicated an increased etch rate of DLC for the higher $f_{LF}/f_{HF}$ combination and for the increased low-frequency power ($P_{LF}$). And the etch rate of DLC was decreased with increasing the $N_2$ flow rate in $O_2/N_2$/Ar plasmas. In order to confirm the application of DLC MLR for the etching process of silicon oxide, the stack of ArF PR/BARC/$SiO_2$/DLC/TEOS/Si was investigated.

• 동의신경정신과학회지
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• 제14권2호
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• pp.135-143
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• 2003

Objectives : The purpose of this study is to analyze and compare heart rate variability(HRV) of patient of twenties and thirties diagnosed as Kiwooljeung with healthy controls'. Methods : We measured HRV of 35 patient(20 to 39 years old, male 14, female 11) diagnosed as Kiwooljeung and 40 healthy controls(male 24, female 16). HRV was measured by SA-3000P(Medicore, Korea) for 5 minutes after 5 minutes resting. Results : 1. In time domain analysis, Mean pulse rate(PRT) in Kiwooljeung group was higher than healthy controls. Standard deviation of all normal N-N intervals (SDNN) in Kiwooljeung group was lower and the results of twenties and thirties were same. 2. In frequency domain analysis, total power(TP), very low frequency(VLF), low frequency(LF), high frequency(HF), Ln TP, Ln VLF, Ln LF, Ln HF in Kiwooljeung group were lower than healthy controls but LF/HF ratio was higher than healthy controls. 3. Comparing gender in Kiwooljeung group, LF/HF ratio in male was higher than female. Conclusions : This study suggests lower activity and imbalance of cardiac autonomous nervous system in Kiwooljeung with the age group between twenties and thirties.