• Title/Summary/Keyword: Quiet-$T_2$

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Comparison of Measurements of Airway Resistance during Panting and Quiet Breathing (Panting 및 Quiet Breathing시 Airway Resistance 측정의 비교)

  • Cheon, Seon-Hee;Lee, Woo-Hyung;Lee, Kee-Young;Kim, Se-Kyu;Chang, Joon;Kim, Sung-Kyu;Lee, Won-Young
    • Tuberculosis and Respiratory Diseases
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    • v.40 no.3
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    • pp.267-273
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    • 1993
  • Background: Panting method for airway resistance measurement has the disadvantages of departing from the normal breathing pattern and of difficult for some patients to perform. We can measure airway resistance during quiet breathing under more physiologic conditions. Airway resistance is often measured during panting but attempts have been made to facilitate resistance measurements during quiet breathing. This study was designed to compare airway resistance measurements during panting with those during quiet breathing. Method: The 24 normal persons and 29 pulmonary disease patients were included in this study. Spirometry was performed and airway resistance measurement was also done during panting and quiet breathing concomittently. Results: The results were as follows; 1) High correlations were found between airway resistance measurements during panting and quiet breathing. 2) Resistance fell during panting, 21.2% in Raw tot, and 22.1% in Raw 0.5. 3) In normal persons, airway resistance fell more during panting when comparing to those in pulmonary disease patients. 4) This was largely independent of thoracic gas volume differences, because the specific airway conductance rose significantly during panting 5) The patients in whom resistance didn't fell during panting was supposed to the patients who couldn't perform panting successively because of high resistance. Conclusions: Although airway resistance can be measured during panting or quiet breathing according to the patient's performance, we must consider resistance fell during panting, by a mean 20%. It may be concluded that quiet breathing is more likely than panting to provide a relevant measurement of airway resistance.

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Usefulness of Acoustic Noise Reduction in Brain MRI Using Quiet-T2 (뇌 자기공명영상에서 Quiet-T2 기법을 이용한 소음감소의 유용성)

  • Lee, SeJy;Kim, Young-Keun
    • Journal of radiological science and technology
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    • v.39 no.1
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    • pp.51-57
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    • 2016
  • Acoustic noise during magnetic resonance imaging (MRI) is the main source for patient discomfort. we report our preliminary experience with this technique in neuroimaging with regard to subjective and objective noise levels and image quality. 60 patients(29 males, 31 females, average age of 60.1) underwent routine brain MRI with 3.0 Tesla (MAGNETOM Tim Trio; Siemens, Germany) system and 12-channel head coil. Q-$T_2$ and $T_2$ sequence were performed. Measurement of sound pressure levels (SPL) and heart rate on Q-$T_2$ and $T_2$ was performed respectively. Quantitative analysis was carried out by measuring the SNR, CNR, and SIR values of Q-$T_2$, $T_2$ and a statistical analysis was performed using independent sample T-test. Qualitative analysis was evaluated by the eyes for the overall quality image of Q-$T_2$ and $T_2$. A 5-point evaluation scale was used, including excellent(5), good(4), fair(3), poor(2), and unacceptable(1). The average noise and peak noise decreased by $15dB_A$ and $10dB_A$ on $T_2$ and Q-$T_2$ test. Also, the average value of heartbeat rate was lower in Q-$T_2$ for 120 seconds in each test, but there was no statistical significance. The quantitative analysis showed that there was no significant difference between CNR and SIR, and there was a significant difference (p<0.05) as SNR had a lower average value on Q-$T_2$. According to the qualitative analysis, the overall quality image of 59 case $T_2$ and Q-$T_2$ was evaluated as excellent at 5 points, and 1 case was evaluated as good at 4 points due to a motion artifact. Q-$T_2$ is a promising technique for acoustic noise reduction and improved patient comfort.

Analysis of the Tsyganenko Magnetic Field Model Accuracy during Geomagnetic Storm Times Using the GOES Data

  • Song, Seok-Min;Min, Kyungguk
    • Journal of Astronomy and Space Sciences
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    • v.39 no.4
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    • pp.159-167
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    • 2022
  • Because of the small number of spacecraft available in the Earth's magnetosphere at any given time, it is not possible to obtain direct measurements of the fundamental quantities, such as the magnetic field and plasma density, with a spatial coverage necessary for studying, global magnetospheric phenomena. In such cases, empirical as well as physics-based models are proven to be extremely valuable. This requires not only having high fidelity and high accuracy models, but also knowing the weakness and strength of such models. In this study, we assess the accuracy of the widely used Tsyganenko magnetic field models, T96, T01, and T04, by comparing the calculated magnetic field with the ones measured in-situ by the GOES satellites during geomagnetically disturbed times. We first set the baseline accuracy of the models from a data-model comparison during the intervals of geomagnetically quiet times. During quiet times, we find that all three models exhibit a systematic error of about 10% in the magnetic field magnitude, while the error in the field vector direction is on average less than 1%. We then assess the model accuracy by a data-model comparison during twelve geomagnetic storm events. We find that the errors in both the magnitude and the direction are well maintained at the quiet-time level throughout the storm phase, except during the main phase of the storms in which the largest error can reach 15% on average, and exceed well over 70% in the worst case. Interestingly, the largest error occurs not at the Dst minimum but 2-3 hours before the minimum. Finally, the T96 model has consistently underperformed compared to the other models, likely due to the lack of computation for the effects of ring current. However, the T96 and T01 models are accurate enough for most of the time except for highly disturbed periods.

CHARACTERISTIC SOLAR WIND DYNAMICS ASSOCIATED WITH GEOSYNCHRONOUS RELATIVISTIC ELECTRON EVENTS

  • Kim, Hee-Jeong;Lee, Dae-Young
    • Journal of Astronomy and Space Sciences
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    • v.21 no.2
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    • pp.93-100
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    • 2004
  • We have investigated characteristic solar wind dynamics associated with relativistic electron events at geosynchronous orbit. Most of the events for April, 1999 through December, 2002 are found to be accompanied by a prolonged solar quiet period which is characterized as low solar wind density, weak interplanetary magnetic field (IMF), and fast alfvenic fluctuations in IMF $B_z$. In a typical relativistic event, electron fluxes begin to increase by orders of magnitude when solar wind parameters drop to low values (e.g., $n_{sw}∼5 cm^{-3}$ and |$B_{IMF}$∼5 nT) after sharp peaks. Then the elevated electron fluxes stay at the high level during the solar quiet period. This observation may suggest the following scenario for the occurrence of a geosynchronous relativistic event: (ⅰ) Quiet solar winds can yield a stable and more dipole-like magnetospheric configurations in which the geosynchronous orbit locates well inside the trapping boundary of the energetic electrons. (ⅱ) If a large population of MeV electrons are generated (by whatever acceleration process(es)) in the inner magnetosphere, they can be trapped and effectively accumulated to a high intensity. (ⅲ) The high electron flux can persist for a number of days in the geosynchronous region as long as the solar wind dynamics stays quiet. Therefore the scenario indicates that the occurrence of a relativistic event would be a result of a delicate balance between the effects of electron acceleration and loss. In addition, the sensitive dependence of a relativistic event on the solar wind conditions makes the prediction of solar wind variability as important as understanding of electron acceleration processes in the forecast of a relativistic event.

Effects of High-heeled Shoe with Different Height on the Balance during Standing and Walking (하이힐 높이에 따른 균형성)

  • Ryu, Ji-Seon
    • Korean Journal of Applied Biomechanics
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    • v.20 no.4
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    • pp.479-486
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    • 2010
  • The purpose of this study was to determine the effects of high-heeled shoe on the quiet standing and gait balance. Twenty women (mean height: $161.6{\pm}3.3\;cm$, mean body mass: $53.8{\pm}6.3\;kg$, mean age: $23.8{\pm}2.7$ yrs..) who were without history or complain of lower limb pain took part in this study. They were asked to stand quietly on a force platform for 30 sec and walk on it at their preferred walking speed (mean speed $3.14{\pm}0.5\;km/hr$.) with wearing three different high-heeled shoe, 3, 7, 9 cm high for collecting data. Data were randomly recorded to collect two trials for quiet standing and five trials for walking The parameters to have been analyzed for comparison between three conditions of the height of high-heeled shoe were COP(Center of Pressure) range, COP velocity, sway area, and free moment on the static balance and COP range, COP velocity, and free moment on the dynamic balance. In this study, high-heel height affected on the COP range and velocity in the ante-posterior direction during walking, dynamic balance, but didn't affect on the quiet standing, static balance.

The Effects of Mothers' Play Beliefs, Children's Gender and Home Play Frequency on Their Play Preferences (어머니의 놀이신념, 유아의 성별과 가정놀이빈도가 유아의 종류별 놀이선호에 미치는 영향)

  • Han, Jun Hee;Choi, Na Ya
    • Korean Journal of Child Studies
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    • v.38 no.2
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    • pp.219-232
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    • 2017
  • Objective: The purpose of this study was to investigate the relationships among mothers' play beliefs, children's gender and home play frequency, and their preferences for three types of play. Methods: Totally 256 mothers of 5-year-olds participated in the survey in metropolitan area. Data were analyzed with t-test, Pearson's correlations, and stepwise multi-regression using SPSS 22.0. Results: First, boys and girls showed little difference in their home play experiences. Boys preferred active and rough play, while girls preferred quiet play. Second, mothers' play beliefs and children's home play frequency had partial correlations with children's play preferences. Third, predictors of children's play preferences were influenced by the types of play. Children's gender and mothers' play beliefs affected children's preference for active play. Only gender explained children's preference for rough play. Finally, children's gender, home play frequency, and mothers' play beliefs influence children's preference for quiet play. Conclusion: In conclusion, gender is an important factor of children's play preferences, and mothers' play beliefs and children's home play frequency affect their preferences for a specific type of play.

The Effect of Human Lower Limb Vibration on Postural Stability during Unstable Posture (불안정한 자세에서 하지에 인가한 진동자극이 자세 안정성 개선에 미치는 영향)

  • Eun, H.I.;Yu, M.;Kim, D.W.;Kwon, T.K.;Kim, N.G.
    • Journal of Biomedical Engineering Research
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    • v.28 no.5
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    • pp.628-635
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    • 2007
  • We studied the effect of vibratory stimulations of different leg muscles, tibialis anterior(TA) and triceps surae(TS), and plantar zones in ten healthy subjects during 1) quiet standing, 2) forward lean of body, 3) backward lean of body, 4) right lean of body, and 5) left lean of body. The experiments were performed on the force platform. The effect of vibration were measured by monitoring the area of COP(Center of pressure) sway. The subjects wore a vibratory stimulation system on foot and ankles and were given the instruction not to resist against the applied perturbations. The results show that all vibratory stimulations to lower limb muscles and plantar zones reduced the COP sway area. This reduction of the COP sway area occurred also in partial vibratory stimulations during quiet standing. In forward lean of body, vibratory stimulations to TA reduced the COP sway area. During backward lean of body, vibratory stimulations to TS reduced the COP sway area. When the subject was tilted right, vibratory stimulations to left plantar zone reduced the COP sway area. During left lean of body, vibratory stimulations to right plantar zone reduced the COP sway area. Thus, the influence of vibratory stimulations to leg muscle and plantar zones differed significantly depending on the lean of body. We suggest that the vibration stimuli from leg muscles and plantar zones could be selectively used to help maintaining postural balance stable.

NEAR REAL-TIME ESTIMATION OF GEOMAGNETIC LOCAL K INDEX FROM GYEONGZU MAGNETOMETER (경주 지자기관측소 자료를 이용한 준실시간 K 지수 산출에 관한 연구)

  • Choi, K.C.;Cho, K.S.;Moon, Y.J.;Kim, K.H.;Lee, D.Y.;Park, Y.D.;Lim, M.T.;Park, Y.S.;Lim, H.R.
    • Journal of Astronomy and Space Sciences
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    • v.22 no.4
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    • pp.431-440
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    • 2005
  • Local K-index is an indicator representing local geomagnetic activity in every 3 hour. For estimation of the local K-index, a reasonable determination of solar quiet curve (undisturbed daily variation of geomagnetic field) is quiet essential. To derive the solar quiet curve, the FMI method, which is one of representative algorithms, uses horizontal components (H and D) of 3 days magnetometer data from the previous day to the next day for a specific day. However, this method is not applicable to real time forecast since it always requires the next day data. In this study, we have devised a new method to estimate local K-index in near real-time by modifying the FMI method. The new method selects a recent quiet day whose $K_p$ indices, reported by NOAA/SEC are all lower than 3, and replace the previous day and the next day data by the recent quiet day data. We estimated 2,672 local K indices from Gyeongzu magnetometer in 2003, and then compared the indices with those from the conventional FMI method. We also compared the K indices with those from Kakioka observatory. As a result, we found that (1) K indices from the new method are nearly consistent with those of the conventional FMI method with a very high correlation (R=0.96); (2) onr local K indices also have a relatively high correlation (R=0.81) with those from Kakioka station. Our results show that the new method can be used for near real-time estimation of local K indices from Gyeongzu magnetometer.

Noise Reducers Effect on Road Traffic Noise (소음저감장치의 도로변 설치 효과 분석)

  • Hong, Yun-H.;Kim, Jeung-T.
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.3 s.120
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    • pp.207-212
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    • 2007
  • Community noise has been great concerned in public. The traffic noise in seoul, especially has been growing awareness for the quiet living environment. In this paper, the effect on the noise barrier in order to reduce highway noise near on the street has been examined. First barriers have been evaluated at 5 locations in the city. The evaluation is performed before and after construction, with the reference point which does not affected on road traffic volume. Then, noise reducers mounted on the harriers also have been examined. the result shows that it reduces noise level by $3{\sim}3.5dB(A)$ with a standard deviation of 2.8 dB(A).

The Comparison of Sleep Characteristics According to the Sleep Positions in Healthy Newborns (정상 신생아의 체위에 따른 수면양상 및 행동변화 비교)

  • Lee Ae Ran;Ahn Hae Young;Lee Jong Soon
    • Child Health Nursing Research
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    • v.5 no.3
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    • pp.281-291
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    • 1999
  • The purpose of this study was to compare the sleep characteristics between the prone and the supine position in healthy newborns. The 48 newborns were observed in the prone position and the supine position respectively on the 2nd day after birth. The data were collected from January to May, 1999. The state of a newborn was classified and categorized to 6 states (deep sleep. light sleep, drowsy, quiet alert, active alert, crying) by Barnard. The movements of eyes, face and extremities, pulse and arterial oxygen were observed and recorded continuously from the start of sleep after feeding until the time of being woken for the next feeding by a trained nurse The data was analyzed by using paired t-test. The results of this study were as follows; 1. There was no significant difference in the length of sleeping time between the prone and the supine position. 2. There was no significant difference in the length and frequencies of each states(deep sleep, light sleep, drowsy, quiet alert, active alert, crying) between the prone and the supine position But the frequency of light sleep in the supine position was significantly higher than that of the prone position. 3 There was no significant difference In the numbers or eyes movements between the prone and the supine sleep position. But the amount of facial and extremity movement in the supine position was significantly higher than those in the prone position 4. There was no significant difference in the arterial oxygen content between the prone and the supine sleep position. 5. There was no significant difference in the heart rates between the prone and the supine sleep position. The above results indicated that the newborns in the prone Position moved less and slept deeper than those in the supine position. though there was no difference in the length of sleep or arterial oxygen content between the prone and the supine sleep Position. But. Nurses and mothers should consider the relationship between the sleep Position and SIDS suggested by previous researches. The infant's 'awakening' during sleep is a normal process and rather valuable because it can provide an opportunity to promote a stronger relationship between mother and baby. So, It is suggested that the supine sleep position is better than the prone sleep position for infants.

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