• Wind and Structures
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• v.21 no.5
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• pp.537-564
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• 2015

Excessive motions in buildings cause occupants to become uncomfortable and nervous. This is particularly detrimental to the tenants and ultimately the owner of the building, with respect to financial considerations. Serviceability issues, such as excessive accelerations and inter-story drifts, are more prevalent today due to advancements in the structural systems, strength of materials, and design practices. These factors allow buildings to be taller, lighter, and more flexible, thereby exacerbating the impact of dynamic responses. There is a growing need for innovative and effective techniques to reduce the serviceability responses of these tall buildings. The current study considers a case study of a real building to show the effectiveness and robustness of the TLD in reducing the coupled lateral-torsional motion of this high-rise building under wind loading. Three unique multi-modal TLD systems are designed specifically to mitigate the torsional response of the building. A procedure is developed to analyze a structure-TLD system using High Frequency Force Balance (HFFB) test data from the Boundary Layer Wind Tunnel Laboratory (BLWTL) at the University of Western Ontario. The effectiveness of the unique TLD systems is investigated. In addition, a parametric study is conducted to determine the robustness of the systems in reducing the serviceability responses. Three practical parameters are varied to investigate the robustness of the TLD system: the height of water inside the tanks, the amplitude modification factor, and the structural modal frequencies.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.2
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• pp.56-61
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• 2010

In this paper, high efficient power amplifier with dual band has been realized. Dual band power amplifier have used modify stub matching for single FET, center frequency 2.14GHz and 5.2GHz respectively. The dual-band operation of the CRLH TL is achieved by the frequency offset and the nonlinear phase slope of the CRLH TL for the matching network of the power amplifier. Because the control of the all harmonic components is very difficult m dual-band, we have managed only the second- and third-harmonics to obtain the high efficiency with the CRLH TL in dual-band. Dual-band characteristics in the output has to balance. Two operating frequencies are chosen at 2.14 GHz and 5.2 GHz in this work. The measured results show that the output power of 28.56 dBm and 29 dBm was obtained at 2.14 GHz and 5.2 GHz, respectively. At this point, we have obtained the power-added efficiency (PAE) of 65.824 % and 69.86 % at two operation frequencies, respectively.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.4
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• pp.27-39
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• 2023

Purpose : The aim of this study was to identify the influence of transient isokinetic exercise on cardiac autonomic modulation and muscle properties in healthy male subjects. Methods : Twenty-eight healthy males underwent isokinetic exercise of both knee joints using a Biodex systems 3 isokinetic dynamometer with an angular velocity of 60 °/sec. The changes in activity of the autonomic nervous system, as determined by heart rate variability (HRV), and in muscle properties were evaluated at three times: pre-exercise, immediately post-exercise, and 10 min post-exercise. Results : The time domain analysis of HRV revealed significant changes in the beat count and mean and minimal heart rate (HR) measured at pre-exercise, immediately post-exercise, and 10 min post-exercise (p<.001). The beat count and mean HR were markedly increased immediately post-exercise compared to pre-exercise, but then significantly decreased at 10 min post-exercise (p<.001). All parameters of the frequency domain were significantly altered by isokinetic exercise (p<.01). The low frequency/high frequency (LF/HF) ratio, as an index for the sympathovagal balance, was elevated by exercise and remained at a similarly high level at 10 min post-exercise (p<.01). The muscle properties of rectus femoris were changed as follows: Muscle tone and stiffness were significantly increased between pre-exercise and immediately post-exercise (p<.001), and between pre-exercise and at 10 min post-exercise (p<.001). Whereas, the elasticity showed no significant change. Conclusion : These results demonstrated that transient isokinetic exercise could induce changes in cardiac autonomic control and muscle properties. In particular, up-regulation of LF/HF ratio after exercise signifies thus enhanced sympathetic modulation by isokinetic exercise. Therefore, it is needed to understand the cardiovascular risks that may arise during isokinetic exercise for providing the basic evidence to establish appropriate isokinetic exercise protocols as effective rehabilitation exercises.

• Journal of Dental Anesthesia and Pain Medicine
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• v.24 no.4
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• pp.273-283
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• 2024

Background: This study evaluated the effect of remimazolam and propofol on changes in autonomic nerve activity caused by surgical stimulation during orthognathic surgery, using power spectrum analysis of blood pressure variability (BPV) and heart rate variability (HRV), and their respective associations with cardiovascular fluctuations. Methods: A total of 34 patients undergoing Le Fort I osteotomy were randomized to the remimazolam (Group R, 17 cases) or propofol (Group P, 17 cases) groups. Observables included the low-frequency component of BPV (BPV LF; index of vasomotor sympathetic nerve activity), high-frequency component of HRV (HRV HF; index of parasympathetic nerve activity), balance index of the low- and high-frequency components of HRV (HRV LF/HF; index of sympathetic nerve activity), heart rate (HR), and systolic blood pressure (SBP). Four observations were made: (1) baseline, (2) immediately before down-fracture, (3) down-fracture, and (4) 5 min after down-fracture. Data from each observation period were compared using a two-way analysis of variance with a mixed model. A Bonferroni multiple comparison test was performed in the absence of any interaction. One-way analysis of variance followed by Tukey's multiple comparisons test was performed when a significant interaction was observed between time and group, with P < 0.05 indicating statistical significance. Results: Evaluation of autonomic nerve activity in comparison with baseline during down-fracture showed a significant increase in BPV LF (P < 0.001), an increasing trend in HRV LF/HF in Group P, and an increasing trend in HRV HF in Group R. There were no significant differences in HR or SBP between the two groups. Conclusion: During down-fracture of Le Fort I osteotomy, sympathetic nerve activity was predominant with propofol anesthesia, and parasympathetic nerve activity was predominant with remimazolam anesthesia.

• Journal of Korea Association of Health Promotion
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• v.4 no.1
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• pp.28-38
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• 2006

Background : Phentermine classified by "sympathomimmetic amie", is a stimulant of sympatheic tone But there has been no concrete study which presents the influence of phentermine on autonomic nervous system. Analysis of Heart rate variability is reliable, non-invasive and very useful for evaluating function of autonomic nervous system. We tried to elucidate the influence of phentermine on autonomic nervovs system by heart rate variability. MethodsAmong the 70 candidates who participated in the double-blind case control study whichwas designed in purpose of approving whether- Adipekⓓ is effective for treatment of obesity, 45persons were folled up. From April, 2005 to May 2005, HRV of the candidates who takes phentermine or placebo for 1month, was recorded using BFM-5000ⓓ(medi-core) for 5 minutes in resting state. HRV measures were assessed by time-domain and by frequency- domain analysis. Time domain parameters contain SDNN(Standard Deviation of NN intervals) and RMSSD(Root-Mean-Square of Successive Differences), etc and frequency domain Parameters contain Total Power(TP), Low frequency(LF'0.04-0.15Hz) power. High Frequency(HF:0.15-0.4Hz) power and LF/HF ratio etc. Results: Intakes of phentermine reduce HRV significant1y. SDNN & RMSSD, the main tine domain parameters of HRV, were decreased significantly(P=0.007. 0.016). PSI(Physical Stress Index of Pressure Index) was increase significantly(P=0.002)The main frequency domain parameters(TP, LF & VLF), also decreased significantly. (P=0.024,0.033, 0.015)Conclusion: The result showed that intakes of phentermine reduce heart rate variability and influence on most parameters of HRV. So phentermine not only accelerates sympathetic tone, but also inhibit the balance and function of autonomic nervous system.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.3
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• pp.253-264
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• 2024

Chronic neuropathic pain (CNP) is a complex condition often arising from neural maladaptation after nerve injury. Understanding CNP complications involves the intricate interplay between brain-heart dynamics, assessed through quantitative electroencephalogram (qEEG) and heart rate variability (HRV). However, insights into their interaction in chronic pain are limited. Resting EEG and simultaneous electrocardiogram (lead II) of the participants were recorded for qEEG and HRV analysis. Correlations between HRV and qEEG parameters were calculated and compared with age, sex, and body mass index (BMI)-matched controls. CNP patients showed reduced HRV and significant increases in qEEG power spectral densities within delta, theta, and beta frequency ranges. A positive correlation was found between low frequency/high frequency (LF/HF) ratio in HRV analysis and theta, alpha, and beta frequency bands in qEEG among CNP patients. However, no significant correlation was observed between parasympathetic indices and theta, beta bands in qEEG within CNP group, unlike age, sex, and BMI-matched healthy controls. CNP patients display significant HRV reductions and distinctive qEEG patterns. While healthy controls exhibit significant correlations between parasympathetic HRV parameters and qEEG spectral densities, these relationships are diminished or absent in CNP individuals. LF/HF ratio, reflecting sympathovagal balance, correlates significantly with qEEG frequency bands (theta, alpha, beta), illuminating autonomic dysregulation in CNP. These findings emphasize the intricate brain-heart interplay in chronic pain, warranting further exploration.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.3
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• pp.259-264
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• 2016

Purpose: To establish the cause of decrease in body stability and to analyze the effects on sensory organs maintaining static balance according to the induced astigmatic blur. Methods: Twenty subjects (10 males, 10 females; mean age, $23.40{\pm}2.70years$) were participated in this study. To induce myopic simple astigmatism, the axis directions of cylindrical lenses were placed $180^{\circ}$ on both eyes (with-the-rule), $90^{\circ}$ on both eyes (against-the-rule), and $45^{\circ}$ on both eyes (oblique). Cylindrical lenses of +0.50, +1.00, +1.50, +2.00, +3.00, +4.00, and +5.00 D were used to increase astigmatic blur in each astigmatism types. General stability (ST) and sway power (SP) in frequencies by each sensory organs were analyzed using the TETRAX biofeedback system. Results: ST in the all astigmatism types were raised with increase of astigmatic blur compared to full corrected condition, but a significant difference only showed in the induced oblique astigmatism. According to the results of correlation analysis between ST and SP in the each frequencies with increase of astigmatic blur, the causes of increased ST in the induced oblique astigmatism showed to have a high correlation in order of somatosensory system (high-medium frequency), central nervous system (high frequency), peripheral vestibular system (low-medium frequency), and visual system (low frequency). Conclusions: The visual information by uncorrected oblique astigmatism may disturb the normal functions of all sensory organs maintaining body balance, consequently, the body stability can be reduced. Therefore, optimal correction of astigmatism can play an important role for reducing the instability of body balance.

• The Korean Journal of Community Living Science
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• v.17 no.3
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• pp.99-107
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• 2006

This study was performed to investigate the dietary habit based on residence types of male college students who registered nutrition course for nonmajor. Self reports on dietary habit and one-day dietary records were obtained from 158 male college students in Chungbuk area. The distribution of residence type of male college student was as follows; self-boarding(43.0%), home(41.1%), boarding with meal(12.7%), and others(3.2%). The mean age of subjects were $22.6{\pm}2.5$, and the mean height and weight were $175.0{\pm}5.6cm\;and\;69.1{\pm}9.3kg$, respectively. The dietary habit of male college students considered to be taken more care of, showing indifference to dietary balance, irregularity of meal, and skipping breakfast. One-day dietary records by 24hr recall methods also showed less diverse food intake(mean DVS, 12.7; mean DDS, 3.92). Especially, the students with self boarding residence were more likely not to eat properly, including indifference to dietary balance, irregularity of meal, skipping breakfast, frequent dining-out, high experience of smoking and drinking, and low DVS and DDS. Also the students with self boarding residence seemed not to make a good choice for food, showing high food intake frequency score in canned food, fast food and instant ramyun, while low score in fruit and fishes. More attention should be taken for self-boarding students to recognize the problems in their own dietary behavior, and more practical suggestion to improve their dietary status would be necessary.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.11a
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• pp.233-244
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• 2002

The purpose of this study is to assess the ability of balance control in moving surround using head mount device and force platform and to examine the clinical usefulness of COP parameters. Fifteen patients with stroke and healthy persons were participated. COP parameters were obtained as total path distance, frequency of anterior-posterior and medial-lateral component by FFT analysis, weight-spectrum analysis in the two different conditions; (1) in comfortable standing with opened or closed eyes, (2) in virtual moving surround delivered using HMD to four different moving pattern. In virtual moving surround setting, moving pattern was composed of close-far, superior-inferior tilting(pitch), right-left tilting(roll) and horizontal rotation(yaw) movement. In all parameters, the reliebility of COP analysis system was significantly high. Also, the construct validity compared between fifteen patients with stroke and normal persons was excellent in virtual moving surround condition(p

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.5
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• pp.485-493
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• 2007

Purpose: Heart rate variability(HRV) is the clinical consequence of various influences of the autonomic nervous system(ANS) on heart beat. HRV can estimate the potential physiologic rhythm from the interval between consecutive beats(RR interval or HRV data). It is known as RSA which represents respiration-related HR rhythmic oscillation. Previous studies demonstrated a specific breathing pattern(0.1Hz, 6breaths/min) to improve a physiological body condition related to the stress. In this paper, the level of stress would be evaluated in terms of three phases of the dental treatment, combined with 6breaths/min. Methods: These phases include before, during and after tooth extraction or anesthesia or something.36 patients' stresses were assessed using HRV stress analyzer in each phase in Kangdong Sacred Heart Hospital, and Chuncheon Sacred Heart Hospital, Hallym University Medical Center from Jun. to Sept. of 2007. HRV 5-min data collected were analyzed in time-domain and frequency-domain to evaluate the activity of autonomic nervous system(ANS) which represents the level of stress. Results: All HRV parameters including HF(high frequency), LF(low frequency) and LF/HF ratio showned a significant change affecting the ANS balance. There was a 6.4% difference between R(LF/HF)s on general breathing pattern for balance of Autonomic nervous system, but on controlled breathing pattern, 0.1Hz, was made narrow till 1.4%. The activity of ANS has increased by 1.4% on general breathing pattern, and by 2.9% on controlled breathing pattern, 0.1Hz. Conclusion: After analysis of preoperative stress changes and effect of breathing pattern of 0.1 Hz on the stress in 36 patients who have undergone third molar extraction, following was concluded. In the preoperative stage, the sympathetic change was the greatest?after the?anesthetic injection, and stress was relieved by controlling the breathing pattern to a frequency of 0.1Hz.