• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
• /
• pp.385-386
• /
• 2009

콘크리트 구조물의 온도균열은 타설 초기 시멘트의 수화열에 의한 온도상승 및 강하에 따라 생기는 체적변화가 내부 또는 외부적으로 구속을 받아 발생하는 것으로, 댐과 같은 매스콘크리트 구조물일수록 온도균열 발생가능성은 높아진다. 이 연구는 성덕 다목적 댐의 수화열 해석을 통해 콘크리트 댐의 시공단계에서 타설 간격에 따른 수화열 발생의 비교 및 수화열에 의한 온도균열 발생 유무를 댐의 내외부 온도차가 수렴하는 장기간 동안에서 비교 분석 하였다.

• 한국농공학회논문집
• /
• 제46권3호
• /
• pp.43-54
• /
• 2004

For a given watershed that consists of urbanized areas, it was essential to predict how the runoff characteristics, such as runoff peak and volume, and travel time, change with time far planning and designing various kinds of hydraulic facilities with given recurrence interval. In this study, Mushim stream watershed was simulated using HEC-HMS model to get runoff characteristics of an urbanization basin. The results was showed that runoff was increased $1794.20{\sim}2104.65\;m^{3}/s$> and $1751.90{\sim}1961.30\;m^{3}/s$ according to the increased of rainfall and CN value recurrence interval in years. Observed storm was increased $497.91{\sim}581.71\;m^{3}/s$ and $506.57{\sim}537.01\;m^{3}/s$ for increased of CN value and impervious area. This paper is also possible to evaluate the effect of urbanization quantitatively.

• The Korean Journal of Physiology and Pharmacology
• /
• 제4권3호
• /
• pp.253-261
• /
• 2000

Head-out water immersion induces marked increase in the cardiac stroke volume. The present study was undertaken to characterize the stroke volume change by analyzing the aortic blood flow and left ventricular systolic time intervals. Ten men rested on a siting position in the air and in the water at $34.5^{circ}C$ for 30 min each. Their stroke volume, heart rate, ventricular systolic time intervals, and aortic blood flow indices were assessed by impedance cardiography. During immersion, the stroke volume increased 56%, with a slight (4%) decrease in heart rate, thus cardiac output increased ${\sim}50%.$ The slight increase in R-R interval was due to an equivalent increase in the systolic and diastolic time intervals. The ventricular ejection time was 20% increased, and this was mainly due to a decrease in pre-ejection period (28%). The mean arterial pressure increased 5 mmHg, indicating that the cardiac afterload was slightly elevated by immersion. The left ventricular end-diastolic volume index increased 24%, indicating that the cardiac preload was markedly elevated during immersion. The mean velocity and the indices of peak velocity and peak acceleration of aortic blood flow were all increased by ${\sim}30%,$ indicating that the left ventricular contractile force was enhanced by immersion. These results suggest that the increase in stroke volume during immersion is characterized by an increase in ventricular ejection time and aortic blood flow velocity, which may be primarily attributed to the increased cardiac preload and the muscle length-dependent increase in myocardial contractile force.

• Archives of Plastic Surgery
• /
• 제39권5호
• /
• pp.489-496
• /
• 2012

Background In Korean women, many of whom have small to moderate-sized breasts, it is difficult to cover a partial breast defect using oncoplastic volume displacement techniques after removal of an adequate volume of tissue during oncologic surgery. In such cases, oncoplastic volume replacement techniques are more useful. Methods From January 2007 to December 2011, 104 women underwent a total of 107 breast-conserving surgeries with various kinds of oncoplastic volume replacement techniques. We used latissimus dorsi (LD) myocutaneous flap for cases in which the resection mass was greater than 150 g. In case with a resection mass less than 150 g, we used regional flaps such as a lateral thoracodorsal flap, a thoracoepigastric flap, or perforator flaps such as an intercostal artery perforator (ICAP) flap or a thoracodorsal artery perforator (TDAP) flap. Results The mean age was 46.1 years, and the average follow-up interval was 10.3 months. The patients underwent oncoplastic volume replacement techniques with a lateral thoracodorsal flap (n=9), thoracoepigastric flap (n=7), ICAP flap (n=25), TDAP flap (n=12), and LD flap (n=54). There was one case of congestion in an LD flap, and two cases of fat necrosis in an ICAP flap. Most of the patients were satisfied with the cosmetic results. Conclusions Oncoplastic volume replacement techniques can be reliable and useful for the correction of breast deformity after breast-conserving surgery, especially in patients with small to moderate-sized breasts.

• Korean Journal of Radiology
• /
• 제21권4호
• /
• pp.450-461
• /
• 2020

Objective: We performed a meta-analysis to evaluate the agreement of cardiac computed tomography (CT) with cardiac magnetic resonance imaging (CMRI) in the assessment of right ventricle (RV) volume and functional parameters. Materials and Methods: PubMed, EMBASE, and Cochrane library were systematically searched for studies that compared CT with CMRI as the reference standard for measurement of the following RV parameters: end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), or ejection fraction (EF). Meta-analytic methods were utilized to determine the pooled weighted bias, limits of agreement (LOA), and correlation coefficient (r) between CT and CMRI. Heterogeneity was also assessed. Subgroup analyses were performed based on the probable factors affecting measurement of RV volume: CT contrast protocol, number of CT slices, CT reconstruction interval, CT volumetry, and segmentation methods. Results: A total of 766 patients from 20 studies were included. Pooled bias and LOA were 3.1 mL (-5.7 to 11.8 mL), 3.6 mL (-4.0 to 11.2 mL), -0.4 mL (5.7 to 5.0 mL), and -1.8% (-5.7 to 2.2%) for EDV, ESV, SV, and EF, respectively. Pooled correlation coefficients were very strong for the RV parameters (r = 0.87-0.93). Heterogeneity was observed in the studies (I² > 50%, p < 0.1). In the subgroup analysis, an RV-dedicated contrast protocol, ≥ 64 CT slices, CT volumetry with the Simpson's method, and inclusion of the papillary muscle and trabeculation had a lower pooled bias and narrower LOA. Conclusion: Cardiac CT accurately measures RV volume and function, with an acceptable range of bias and LOA and strong correlation with CMRI findings. The RV-dedicated CT contrast protocol, ≥ 64 CT slices, and use of the same CT volumetry method as CMRI can improve agreement with CMRI.

• 한국산학기술학회논문지
• /
• 제19권10호
• /
• pp.515-522
• /
• 2018

본 연구는 속도 방식에 따른 보행훈련이 일반 성인의 호흡기능에 어떠한 영향을 미치는지 알아보고자 하였다. 연구 대상자 37명을 세 그룹으로 나누어 각각 속보, 평보, 교대 보행훈련을 실시하였다. 보행 훈련은 트레드밀 위에서 시행되었고, 60분간 시행하였으며 주당 3회, 6주간 실시하였다. 흡기 압력과, 최대 흡기량 및 가로막 움직임 크기 변화가 측정되었고, 반복 측정분산분석을 사용하여 시간별, 집단간 차이 및 상호작용을 분석하였다. 흡기 압력의 경우 시기에 따라 유의한 차이가 있었으며, 시기와 집단 간의 상호작용에서 유의한 차이가 있었다. 최대 흡기량의 경우 역시 시기에 따라 유의한 차이가 있었으며, 시기와 집단 간의 상호작용에서 유의한 차이가 있었다. 가로막 움직임 크기 변화의 경우 시기에 따라 유의한 차이가 있었고, 시기와 집단 간의 상호작용에서 또한 유의한 차이가 있었으며, 각 그룹 간에 유의한 차이가 있었다. 사후검정을 시행한 결과 교대군과 평보군 사이에 유의한 차이가 있었다. 이상과 같은 결과로 볼 때 빠른 속도와 느린 속도를 병행하는 보행 훈련이 가로막 움직임 변화에 더 긍정적인 효과를 나타내는 것을 알 수 있었다.

• 대한약리학회지
• /
• 제31권2호
• /
• pp.251-259
• /
• 1995

Pharmacokinetics and pharmacodynamics of metoprolol, a selective beta-l blocker, were examined for 360 minutes after intravenous bolus administration of metoprolol to 6 dogs. Plasma concentration and excreted amount in the urine metoprolol were measured by liquid chromatography with fluorescence detection. PR interval and heart rate were measured by ECG monitoring. Blood pressure was monitored through intraarterial catheter in femoral artery and cardiac output by thermodilution method using Swan-Ganz catheter. To analyze the effect site concentration-response relationship, plasma concentration and pharmacological effects were simultaneously fitted to a two pharmacokinetic compartment linked to pharmacodynamic model with NONLIN program. Results are as follows. 1) The plasma concentration of metoprolol after intrvenous injection decreased biexponentially. The terminal half-life estimated was $1.33{\pm}0.40$ hours and the volume of distribution at steady state (Vdss) and the total body clearance were $1.04{\pm}0.4\;L/kg,\;6.55{\pm}2.21\;L/hr$, respectively. The central compartment volume of distribution and peripheral compartment volume of distribution were $0.35{\pm}0.14L/kg\;and\;0.69{\pm}0.34L/kg$. The renal clearance and intercompartment clearance were $0.53{\pm}0.25\;L/min\;and\;0.35{\pm}0.19\;L/min$. 2) Simulated biophase concentration-response curve shows hyperbolic relationship and the estimated concentration-effect relationship was best explained by Emax model when the prolongation of PR interval and the reduction of the heart rate were used as pharmacodynamic parameters. Emax and EC50 were estimated to be $26.3{\pm}4.7\;msec\;and\;88.8{\pm}82.3\;g/ml$ for PR interval, and $48.7{\pm}18.8\;beats/min\;and\;113.5{\pm}78.7\;ng/ml$ for heart rate, respectively. 3) The changes of cardiac output-effect site concentration relationship was best fitted by a linear model and the slope of the relationship was $0.005{\pm}0.003$. Diastolic blood pressure-effect site concentration relationship was also explained by the linear model and the slope of the relationship was $0.038{\pm}0.034$.

• 오토저널
• /
• 제15권3호
• /
• pp.120-125
• /
• 1993

The surface roughness of workpiece is reduced during spark-out. The reduction of roughness is a benefit of spark-out, but spark-out lowers productivity. The characteristics of spark-out are different to those of plunge grinding to which feed is applied. This difference is due to overlapping cutting during spark-out. Effect of spark-out is in proportion to volume of grain wear. This phenomenon is due to different overlapping area. Dressing interval can be enlarged by spark-out, when volume of grain wear is large. In this study, the characteristic of spark-out was studied by spark-out obserbation in various grinding conditions. For this purpose thrust force, spark-out time and surface roughness of workpiece were experimentally investigated in various grinding conditions.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 D
• /
• pp.2492-2494
• /
• 2003

Urine analysis is one of the most important medical examination in the hospital. Not only the data for the ingredients of urine through chemical analysis, but also the data related to fluid dynamics, e.g., peak flow rate, average flow rate, may provide some useful information about patient's state of health. Therefore, we develop the portable system to measure and analyse fluid volume/flow rate in this study. This system can store and print the measured data during the pre-specified time interval, and provide some meaningful data related with fluid dynamics. We explain the method and the technical stuff to implement the system, and show the result.

• 한국환경과학회지
• /
• 제31권11호
• /
• pp.941-950
• /
• 2022

This study was conducted to provide data and stem information to establish a local volume table of Cryptomeria japonica in Jeju Island. Stem analysis was performed on 26 trees by selecting two average trees from each site of the 13 plots of C. japonica stands in 2021 and 2022. During the analysis stage, one outlier tree was rejected, and a total of 260 observations of the specific stem height of 25 trees were used. Of the seven major taper equation models applied for parameter estimation and statistical verification, the Muhairwe 1999 model was found to be the best fit and selected as the optimal model. Stem shape-related estimates were acquired through the selected model, and sectional measurements according to the Smalian formula applied at an interval of 10 cm from the height of the stem were used to develop a volume table. A paired t-test comparison between the C. japonica volume obtained from the present study and those selected from the current yield table by NIFoS(2020), revealed significant differences (p<0.05), highlighting the necessity of a local volume table for C. japonica in Jeju Island.