• Tuberculosis and Respiratory Diseases
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• v.52 no.4
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• pp.346-354
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• 2002

Background : Dyspnea and a limitation in exercise performance are important cause of disability in patients with chronic obstructive pulmonary disease(COPD). A depleted nutritional state is a common problem in patients with a severe degree of chronic airflow limitation. This study was carried out to assess the factors determining the maximum exercise capacity in patients with COPD. Methods : The resting pulmonary function, nutritional status, and maximum exercise performance was assessed in 83 stable patients with moderate to severe COPD. The nutritional status was evaluated by bioelectrical impedance analysis. Maximum exercise performance was evaluated by maximum oxygen uptake($VO_2max$). Results : Among the 83 patients, 59% were characterized by nutritional depletion. In the depleted group, a significantly lower peak expiratory flow rate(p<0.05), Kco(p<0.01) and maximum inspiratory pressure(p<0.05), but a significantly higher airway resistance(p<0.05) was observed. The maximum oxygen uptake and the peak oxygen pulse were lower in the depleted group. The $VO_2max$ correlated with some of the measures of the body composition : fat-free mass(FFM), fat mass(FM), body mass index(BMI), intracellular water index(ICW index), and pulmonary function : forced vital capacity(FVC), forced inspiratory vital capacity(FIVC), diffusion capacity(DLCO) : or maximum respiratory pressure : maximum inspiratory pressure(PImax), maximum expiratory pressure(PEmax). Stepwise regression analysis demonstrated that the FFM, DLCO and FIVC accounted for 68.8% of the variation in the $VO_2max$. Conclusion : The depletion of the FFM is significant factor for predicting the maximum exercise performance in patients with moderate to severe COPD.

• Journal of Chest Surgery
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• v.29 no.1
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• pp.1-6
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• 1996

We developed an experimental model of brain death using dogs. Brain death was induced by increasing the intracranial pressure (ICP) gradually by continuous Infusion of saline through an epidural Foley catheter in 5 mongrel dogs (weight, 18~22kg). Hemodynamic and electrocardiographic changes were evaluated continuously during the process of brain death and obtained the following results. 1. The average volume and time required to induce brain death was 4.8$\pm$1.0ml and 143.0$\pm$30.9minutes respectively. 2. There was a steady rise of the ICP after starting the constant infusion of saline, and ICP rised continuously until the brain death (122.0$\pm$62.5mmHg). After reaching to the maximal value (125.0$\pm$47.7mmHg) at 30 minutes after brain death, the ICP dropped and remained approximately constant at the slightly higher level than the mean arterial pressure (MAP). 3. MAP showed no change until the establishment of brain death and it declined gradually. The peak heart rate reached to 172.6$\pm$35.3/min at 30 minutes after the brain death. 4. Even though the body temperature and all hemodynamic variables, such as cardiac output, mean pulmonary arterial pressure, left ventricular (LV) end-diastolic pressure and LV maximum + dp/dt, were slightly greater than those of basal state, at the point of brain death, there was no statistically significant change during t e process of brain death. 5. There was no remarkable arrhythmias during the experiment except ventricular premature beats which was observed transiently in one dog at the time of brain death. Hemodynamic changes in the brain death model induced by gradual ICP increment were inconspicuous, and arrhythmias were rarely seen. Hyperdynamic state, which was observed at the point of brain death in another brain death model caused by abrupt ICP increase, was not observed.

• Wind and Structures
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• v.7 no.5
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• pp.317-332
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• 2004

Wind tunnel experiments were conducted under highly turbulent and disturbed flow conditions over a solid/perforated plate with a long splitter plate in its plane of symmetry. The effect of varied level of perforation of the normal plate on fluctuating velocities and fluctuating pressures measured across and along the separation bubble was studied. The different perforation levels of the normal plate; that is 0%, 10%, 20%, 30%, 40% and 50% are studied. The Reynolds number based on step height was varied from $4{\times}10^3$ to $1.2{\times}10^4$. The shape and size of the bubble vary with different perforation level of the normal plate that is to say the bubble is reduced both in height and length up to 30% perforation level. For higher perforation of the normal plate, bubble is completely swept out. The peak turbulence value occurs around 0.7 to 0.8 times the reattachment length. The turbulence intensity values are highest for the case of solid normal plate (bleed air is absent) and are lowest for the case of 50% perforation of the normal plate (bleed air is maximum in the present study). From the analysis of data it is observed that $\sqrt{\overline{u^{{\prime}2}}}/(\sqrt{\overline{u^{{\prime}2}}})_{max}$, (the ratio of RMS velocity fluctuation to maximum RMS velocity fluctuation), is uniquely related with dimensionless distance y/Y', (the ratio of distance normal to splitter plate to the distance where RMS velocity fluctuation is half its maximum value) for all the perforated normal plates. It is interesting to note that for 50% perforation of the normal plate, the RMS pressure fluctuation in the flow field gets reduced to around 60% as compared to that for solid normal plate. Analysis of the results show that the ratio [$C^{\prime}_p$ max/$-C_{pb}(1-{\eta})$], where $C^{\prime}_p$ max is the maximum coefficient of fluctuating pressure, $C_{pb}$ is the coefficient of base pressure and ${\eta}$ is the perforation level (ratio of open to total area), for surface RMS pressure fluctuation levels seems to be constant and has value of about 0.22. Similar analysis show that the ratio $[C^{\prime}_p$ max/$-C_{pb}(1-{\eta})]$ for flow field RMS pressure fluctuation levels seems to be constant and has a value of about 0.32.

• The Journal of the Petrological Society of Korea
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• v.10 no.2
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• pp.57-81
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• 2001

In the amphibolites of the Hwanggangri area, three metamorphic zones are established like hornblende-actinolite zone (H-AZ), hornblende zone (HZ) and diopside zone (DZ) by the main mineral assemblages. Hornblende zone and hornblende-actinolite zone develope away from the diopside zone that experienced the highest thermal effect. Thus, this pattern identifies the decreasing metamorphic grade of the contact metamorphism with increasing distance from the granitic pluton. The mineral assemblages of this rock are classified into six representative groups such as $\circled1$ actinolite+plagioclase+chlorite, $\circled2$ actinolite+hornblende+plagioclase+chlorite$\pm$epidote$\pm$biotite, $\circled3$ actinolite+hornblende+plagioclass$\pm$biotite$\pm$epidote, $\circled4$ hornblende+plagioclase$\pm$biotite$\pm$chlorite, $\circled5$ hornblende+plagioclase+diopside+actinolite$\pm$epidote$\pm$chlorite, $\circled6$hornblende+plagioclase+diopside$\pm$biotite$\pm$epidote. Two metamorphic events m recognized in the amphibolites of the study area that the first metamorphism is the regional metamorphism dominantly occurred in the whole Ogcheon metamorphic belt and it gave rise to the growth of actinolite at the core or center of the amphibole grains of coarse and medium size. Its metamorphic grade ranges from the greenschist facies to epidote-amphibolite facies. The second metamorphism overlapped is the contact metamorphism caused by the adjacent granitic pluton, and its metamorphic grade is thought to reach to the low pressure part of upper amphibolite facies. According to the calculation by TWEEQU thermobarometry and amphibole-plagioclase thermometry, the metamorphic temperature of initial regional metamorphism is $439-537^{\circ}C$ under pressure of 4.6-7.3 kb and its peak temperature and pressure are considered to reach to the range of 492-537 and 5.2-7.3 kb. And the temperature range of contact metamorphism occurred by intrusion of cretaceous granitic body, is $588-739^{\circ}C$ under pressure of 2.6-5.2 kb and its peak temperature and pressure are estimated as having the range of $697-739^{\circ}C$ and 3.8-5.2 kb that this amphibolites are estimated to pass through the metamorphic evolution of both the rise of temperature and the drop of pressure.

• Korean Journal of Applied Biomechanics
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• v.26 no.2
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• pp.143-151
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• 2016

Objective: The purpose of this study was to investigate the effect of fatigue induction on ground reaction force (GRF) components, postural stability, and vertical jump performance in Taekwondo athletes. Method: Ten Taekwondo athletes (5 men, 5 women; mean age, $22.30{\pm}2.62years$; mean height, $174.21{\pm}9.20cm$; mean body weight, $67.28{\pm}12.56kg$) participated in this study. Fatigue was induced by a short period of strenuous exercise performed on a motorized treadmill. The analyzed variables included vertical jump performance, static stability (mediolateral [ML], center of pressure [COP], anteroposterior [AP] COP, ${\Delta}COPx$, ${\Delta}COPy$, and COP area), postural stability index values (ML stability index [MLSI], AP stability index [APSI], vertical stability index [VSI], dynamic postural stability index [DPSI]), and GRF components (ML force, AP force, peak vertical force [PVF], and loading rate). To analyze the variables measured in this study, PASW version 22.0 was used to calculate the mean and standard deviation, while a paired t-test was used to evaluate the pre- versus post-fatigue results. Pearson's correlation coefficients among variables were also analyzed. The statistical significance level was set at ${\alpha}$ = .05. Results: Vertical jump performance decreased significantly after the induction of fatigue, while AP COP, ${\Delta}COPx$, COP area, APSI, VSI, and DPSI increased significantly. PVF and loading rate increased significantly after the induction of fatigue, while the postural stability variables (AP COP, ${\Delta}COPy$, COP area, APSI, VSI, DPSI) were similarly correlated with GRF components (PVF, loading rate) after fatigue was achieved (r = .600, $R^2$ = 37%). Conclusion: These results suggest that the induction of fatigue can decrease postural stability and exercise performance of Taekwondo athletes during training and competition sessions.

• Korean Journal of Applied Biomechanics
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• v.24 no.1
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• pp.43-50
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• 2014

The purpose of this study was to analyze of the GRF (ground reaction force) parameters according to the change of positions and weights of bag during downward stairs between dominant and non-dominant in upper & lower limbs. To perform this study, participants were selected 9 healthy women (age: $21.40{\pm}0.94yrs$, height: $166.50{\pm}2.68cm$, body mass: $57.00{\pm}3.61kg$, BMI: $20.53{\pm}1.03kg/m^2$), divided into 2 carrying bag positions (dominant arm/R, non-dominant arm/L) and walked with 3 type of bag weights (0, 3, 5 kg) respectively. One force-plate was used to collect GRF (AMTI OR6-7) data at a sample rate of 1000 Hz. The variables analyzed were consisted of the medial-lateral GRF (Fx), anterior-posterior GRF (Fy), vertical GRF (Fz), impact loading rate and center of pressure (COPx, COPy, COP area, COPy posterior peak time) during downward stairs. 1) The Fx, Fy, Fz, COPx, and COP area of GRF were not statistically significant between dominant leg and non-dominant leg, but non-dominant leg, that is, showed the higher COPy, and showed higher impact loading rate than that dominant leg during downward stairs. 2) In bag wearing to non-dominant arm, Fx, Fz, COPx, COPy, impact loading rate and COP area showed increase tendency according to increase of bag weights. Also, against bag wearing to dominant arm, non-dominant showed different mechanism according to increase of bag weights. The Ground Reaction Force parameters showed different characteristics according to the positions and weights of bag during downward stairs between dominant and non-dominant arm.

• Journal of Veterinary Clinics
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• v.27 no.6
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• pp.735-739
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• 2010

An 8 month old female Maltese (body weight 3.6 kg) was referred with primary complaints of dyspnea and exercise intolerance. Diagnostic imaging studies revealed marked cardiomegaly and prominent main pulmonary trunk dilation on thoracic radiography, abnormally arisen aortic roots (toward right ventricle) with left-to right shunted perimembraneous ventricular septal defect located underneath of aortic root, aortic root was located to predominantly to the right ventricle and pulmonary regurgitation (peak velocity 4.7 m/s, pressure gradient ~88 mmHg) from pulmonary over-circulation and hypertension on echocardiography, indicating double outlet right ventricle (DORV). The dog was treated with furosemide (1 mg/kg, BID) for reducing volume overload at right ventricle, spironolatcone (1 mg/kg) and enalapril (0.5 mg/kg) for minimizing deleterious cardiac remodeling, and sildenafil (1 mg/kg) for lessening pulmonary over-circulation and hypertension. The clinical condition of this dog was improved after 1 week of medical treatment. The dog is currently survived and regularly monitored.

• Journal of Biomedical Engineering Research
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• v.31 no.3
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• pp.210-216
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• 2010

This study is vestibular electric stimulation applied between the mastoids during quiet standing elicits postural sway. The aim of this study was to characterize the postural sway response to continuous sinusoidal vestibular electric stimulation across various stimulus frequencies and amplitudes. Binaural bipolar sinusoidal vestibular electric stimulation was applied to the skin overlying the mastoid processes of 10 subjects while they stood on a force plate. The position of the center of pressure(COP) and signals at the feet are obtained on an force plate, while the head and whole body center of mass(COM) was measured with motion analysis system. The stimulus conditions included eight frequencies (1/64, 1/32, 1/16, 1/8, 1/4, 1/2, 1, and 2Hz) and six peak amplitudes (0.1, 0.25, 0.5, 0.7, 1 and 2mA). Each subject experienced one trial at each amplitude-frequency pair. The stimuli elicited sway in lateral plane in all subjects, as evidenced by changes in the stimulus frequency. Our results demonstrate that the vestibular system is sensitive to vestibular electric stimulation intensity changes and responds by altering the magnitude of the response accordingly.

• Biomedical Science Letters
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• v.19 no.1
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• pp.61-69
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• 2013

The aim of this study was to evaluate the effect of exercise-based cardiac rehabilitation on pro- and anti-inflammatory markers in patients with acute coronary syndrome (ACS). ACS patients who underwent percutaneous coronary intervention (PCI) and took medicine during phase II of rehabilitation were recruited for study. Subjects were divided into two groups; exercise group (EX, n=21) and a non-exercise group (non-EX, n=13). Supervised exercise program in hospital consisted of treadmill and bicycle exercise was performed three times per week for 6 weeks. Patients of EX received individual counseling, including knowledge of heart disease, risk factor modification, and physical training. Cardiopulmonary fitness, body composition, and biochemical blood factors were analyzed before and after experiment. There was no significant difference in serum levels of hs-CRP and TGF-${\beta}1$ between groups, and between time intervals. But there was a significant decrease in serum levels of IL-18 (P<.001). And there was a significant increase in ratio of IL-18 to IL-10 (P<.01) and serum levels of IL-10 (P<.001). After cardiac rehabilitation, there was significant increase in exercise duration (P<.001), maximal oxygen uptake ($VO_{2peak}$; P<.001) and decrease in submaximal rate-pressure product (sRPP; P<.05) in EX. In conclusion, exercise-based cardiac rehabilitation during phase II in patients with ACS after PCI decreased serum IL-18 (pro-inflammatory) content and ratio of IL-18 to IL-10 in serum (highly related with disease recurrence), and increased serum IL-10 (anti-inflammatory) content. In addition, it led to improved cardiopulmonary fitness.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.904-907
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• 2002

Optical disk drive device is improved in rotating speed for faster data reading. In the case of CD-ROM, rotating speed is over 10000 rpm in the practical use. As a result of high rotating speed, unexpected effects as like increasing disk fluctuation and acoustic noise are raised by the air friction on the rotating disk and the eccentricity of rotating parts. The overall acoustic noise of running CD-ROM could be classified into two different characterized noise. The first is the structural-borne noise which is generated from vibrating solid body. By the reason, the signal of structural borne noise has very similar to the signal of surface vibrating one. It has dense noise energy at specific frequency region. The other is the air-borne noise which is generated from turbulence or vortex caused by friction between disk and air. The signal of air-borne noise has no dominant peak point at acoustic pressure-frequency domain. The noise energy is widely distributed while comparatively high and large frequency region. The structural-borne noise could be reduced by reducing vibration of structure and in addition it's target reducing frequency is narrow. However the air-borne noise reduction is effectively needed of enclosing method for the noise source located near the disk surface because it is difficult to define target frequency point. In this study, the acoustic noise at driving CD-ROM is classified by the sides of it's character and tried to reduce the overall acoustic noise.