• Journal of Chest Surgery
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• v.38 no.1 s.246
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• pp.63-66
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• 2005

Surgical anterior ventricular endocardial restoration (SAVER) is a technique that improves hemodynamic status by excluding akinetic or dyskinetic portions of the left ventricle, restores the ventricle to normal elliptical shape and reduces ventricular wall tension to normal level in patients with acute anterior wall myocardial infarction that accompanies aneurysm. We performed redo-SAVER procedure in a 40-year old man with remodeled dilated ventricle who had already underwent LV aneurysmectomy 12 years earlier, and the results were satisfactory.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.3
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• pp.152-157
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• 1999

Oil leaked from underwound storage tanks and leachate from sanitary landfills have been known as contaminant sources of the high-quality groundwater resources. The mobility of contaminants in the aquifer largely depends on the groundwater flow and the determination of associated hydraulic parameters is essential for a proper remediation of contaminated grnundwater. This study aimed at determining an optimum set of hydraulic parameters for an unconfined sandy aquifer of a laboratory scale through comparison of various methods. Results showed that the specific yield obtained from gravity drainage experiment was an average of 0.20 with minor variations in aquifer depths. and the permeabilities obtained from Dupuit approximation and slug test gave similar values of 5.33 cm/min and 5.85 cm/min but the constant head method gave 0.17 cm/min, which is much ion than the other methods. This experimental evidence reveals that the permeability of the unconfined sandy aquifer could be accurately determined by Dupuit assumption or slug tut rather than by constant head method conducted for a disturbed separate soil column.

• Childhood Kidney Diseases
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• v.6 no.1
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• pp.68-74
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• 2002

Purpose: Suprapubic bladder aspiration(SBA) of urine is the most reliable method to obtain urine avoiding contamination in non-toilet trained infants. Ultrasonography is a useful tool for guiding the anatomic location as well as for direct visualization during procedure. We evaluated the success rate and complication of ultrasound(US) assisted SBA Methods. Sixty infants who visited Ewha Womans University Mokdong Hospital, with suspected urinary tract infection were randomly divided into the US assisted (n=32) and blind SBA(control, n=28) group. In US assisted SBA group, the anteroposterior(AP), transverse, and sagittal diameters and the volume of the bladder were measured. In the blind SBA group, urine was blindly aspirated when the urinary bladder was palpated at the suprapubic area. The rate of successful urine aspiration, the number of attempts until successful aspiration, aspirated urine volume were compared between the two groups. Results: The success rate was $100\%$(32/32) in the US assisted group, which was significantly higher than $85.7\%$(24/28) of the control group (P<0.05). The aspirated urine volume in the US assisted group was $7.4{\pm}3.7\;mL$, which was significantly higher than $4.5{\pm}3.4\;mL$ of the control group (P<0.05), The diameters and volume of bladder in successful aspiration were $2.1{\pm}0.7\;cm$ in AP diameter, $3.1{\pm}0.6\;cm$ in transverse diameter, $4.2{\pm}1.0\;cm$ in sagittal diameter and $15.2{\pm}10.4\;mL$ in volume, which were significantly higher than those ($1.7{\pm}0.3\;cm,\;1.7{\pm}0.3\;cm,\;1.8{\pm}0.7\;cm,\;2.4{\pm]0.6\;cm,\;3.9{\pm}2.5$) of the control group (P<0.05) The correlations between the AP(r=0.78), transverse (r=0.72), sagittal(r=0.91) diameter and bladder volume were significant (P<0.05). SBA was $100\%$ successful in the AP diameter >3 cm, transverse diameter >4 cm, depth >4 cm and bladder volume >5 mL. Conclusion: US assistance can significantly improve the success rate of SBA in infant with suspected urinary tract infection. (J Korean Soc Pediatr Nephrol 2002 ; 6 : 68-74)

• Clinical and Experimental Pediatrics
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• v.53 no.1
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• pp.21-27
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• 2010

Purpose : In contrast with traditional time-cycled, pressure-limited ventilation, during volume-controlled ventilation, a nearly constant tidal volume is delivered with reducing volutrauma and the episodes of hypoxemia. The aim of this study was to compare the efficacy of pressure-regulated, volume controlled ventilation (PRVC) to Synchronized intermittent mandatory ventilation (SIMV) in VLBW infants with respiratory distress syndrome (RDS).Methods : 34 very low birth weight (VLBW) infants who had RDS were randomized to receive either PRVC or SIMV with surfactant administration : PRVC group (n=14) and SIMV group (n=20). We compared peak inspiratory pressure (PIP), duration of mechanical ventilation, and complications associated with ventilation, respectively with medical records. Results : There were no statistical differences in clinical characteristics between the groups. After surfactant administration, PIP was significantly lower during PRVC ventilation for 48hrs and accumulatevive value of decreased PIP was higher during PRVC ventilation for 24hrs (P<0.05). Duration of ventilation and incidence of complications was no significant difference. Conclusion : PRVC is the mode in which the smallest level of PIP required to deliver the preset tidal volume in VLBW infants with RDS, adaptively responding to compliance change in lung after surfactant replacement.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.3
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• pp.220-230
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• 1992

Soil temperature is one of the important environmental factors which control all the physical, chemical and biological processes in soil including germination and root growth of plants and other organisms living in the soil ecosystem. Soil water and nutrient availability and mobility are temperature dependent. Soil temperature change is depended primarily upon energy exchange in soil surface, meteorological variance and physical properties of the soils which are closely related to heat transfer mechanism. In this study physical properties including bulk density, soil texture and organic matter content were measured and thermal diffusivity on the soils was calculated. Soil samples from the 66 meteorological stations under the Korea Meteorology were collected and the physical parameters were measured. To obtain relationship between thermal diffusivity and soil water content a heat probe thermal diffusivity measurement apparatus was designed and used in this experiment. According to the survey on soil physicsal properties on the 66 meteorological stations, the 52% of the surface soil texture were sandy loam and laomy sand or sand, 38% were loam and silty loam, and 10% were clay loam and silty clay loam. The bulk density which was closely related with thermal properties showed average of $1.41g/cm^3$ for sandy soils, $1.33g/cm^3$ for loam and silty loam soils, and $1.21g/cm^3$ for clay loam and silty clay loam soils. The apparent thermal diffusivity of the upper layer from 0 to 30cm ranged from 1.16 to $8.40{\times}10^{-3}cm^3/sec$ with average of $3.53{\times}10^{-3}cm^3/sec$. The apparent thermal diffusivities of the Jeju soils of which organic matter contents were high and the bulk densities were low were near $2{\times}10^{-3}cm^3/sec$. The thermal diffusivity of snow measured in Chuncheon ranged from 0.822 to $2.237{\times}10^{-3}cm^3/sec$. The damping depth calculated from the thermal diffusivity ranged from 5.92 to 13.65cm for daily basis and 124 to 342cm for yearly basis. The significant regression equation to estimate thermal diffusivity with bulk density and soil water content was obtained by the heat probe in laboratory.

• Korean Journal of Environment and Ecology
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• v.38 no.2
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• pp.217-226
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• 2024

This study aimed to investigate the influence of anions in the air on the purification of fine dust (PM10 and PM2.5) and to evaluate the effects of plants on the generation of anions in the air and the purification of fine dust. Subsequently, the fine dust reduction models were compared according to each factor and plant volume. The characteristics of anion generation by each factor were observed to be in the order of Type N.I (negative ion generator; 204,133.33 ea/cm³) > Type P₃₀ (plant vol. 30%; 362.55 ea/cm³) > Type C (control; 46.22 ea/cm³), indicating that the amount of anion generation in the anion generator treatment group and the plant arrangement group were approximately 4,417 times and 7 times higher, respectively, than that in the untreated group. Consequently, the fine dust reduction characteristics by anion generation source showed that for PM10, Type NI had a purification efficiency 2.52 times higher than Type C, and Type P₃₀ was 1.46 times higher, while for PM2.5, Type NI had a purification efficiency 2.26 times higher than Type C, and Type P₃₀ was 1.31 times higher. The efficiency of fine dust purification by plant volume was in the order of Type P₂₀ (84.60 minutes) > Type P₃₀ (106.50 minutes) = Type P₂₅ (115.50 minutes) = Type P₁₅ (117.60 minutes) > Type P₅ (125.25 minutes) = Type P₁₀ (129.75 minutes), and for ultrafine dust, Type P₂₀ (104.00 minutes) > Type P₃₀ (133.20 minutes) = Type P₂₅ (144.00 minutes) = Type P₁₅ (147.60 minutes) > Type P₅ (161.25 minutes) = Type P₁₀ (168.00 minutes). Thus, a quantitative analysis of the anions and plants for purifying fine dust and suggested matters to be considered for future green space planning and plant planting considering fine dust purification.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.3
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• pp.82-88
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• 2013

In this project a preliminary experimental research work was done to apply mortars containing magnetite as fine aggregates unto floor finishing materials in order to make indoor environment eco-friendly and to have noiseproof control between floors. Crushed magnetites were substituted as sands in the mix design with a range of 0, 20, 40, 60, 100%. First far-infrared radiation tests to determine emissivity and emission power were done in accordance with the KICM test standard and an outstanding result was obtained. Density and compressive strength test results also showed that as the substitution increases, test values increase in a linear trend. However dry shrinkage test results revealed that as the substitution increases, shrinkage strain also increases. To clearly seek a solution about this problem, more experimental works should be done on oncoming experimental program.

• The Journal of Engineering Geology
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• v.7 no.2
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• pp.91-99
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• 1997

In general, there are various approaches available in literature to model discontinuous rock masses and engineers are often confused which one to use for designing structures in rock masses. Modelling rock masses can be classified mainly into two approaches. One is discrete modelling of intact rock and discontinuities and the other is the equivalent continuum modelling. In this study five models are selected ;(1) Crack tensor model, (2) Equivalent volume defect model, (3) Damage model, (4) Micro - structure model (Parallel model and Series model), and (5) Homogenization model. Most of these models are mainly concerned with how to define additional strain due to discontinuities over the representative elementary volume (REV) and how to relate the stress field of discontinuities to that acting on the REV. The characteristics of these models are clarified by comparing with results of some laboratory tests.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.989-992
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• 2008

In this paper, we are presenting a case that integrates ultra high strength concrete(150MPa) with surface-exposed concrete. Ahead of the field application, we carried out laboratory experiment and B/P Test for a basic property of concrete(slump flow, air content, 50cm flow time, elapse time change and compression strength) and productivity. The next, we conducted Mock-up Test using simulation specimen to evaluate infilling, surface-finishing and hydration heat of concrete. We had satisfactory results for a basic property and hydration heat of concrete. However at the time of field application, it was occurred rupture of formwork because of high lateral pressure of concrete, and then formwork was reinforced and case-in-place time was adjusted. And regardless of low and high frequency vibration, it occurred to surface-pockmark. In case that applies ultra high strength concrete to surface-exposed concrete, we estimate that it is important of systematic management and improvement of construction.

• Journal of the Korean Solar Energy Society
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• v.22 no.3
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• pp.1-10
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• 2002

Relatively being economical in installation and easy in operation, hot-air heating system has been generally used in greenhouse for heating system regardless of high cost in maintenance and uneven distribution of air temperature. Therefore to overcome the disadvantages in maintenance and in distribution of air temperature and to improve efficiency of heating system, this experimental study is performed. This experimental study aims to improve the character of uneven temperature distribution in vertical direction and to reduce energy consumption for heating in a greenhouse. The experiment had been performed to investigate change of thermal environment and effects on reducing energy consumption for heating in greenhouse by additional surface insulation and reduction of indoor-air volume that come by installing transparent vinyl membranes with different height in each house. The results show that there is a wide difference in oil-energy consumption between houses according to condition of surface insulation and change of indoor-air volume. Furthermore, the results show that the efficiency of dual surface is higher than that of change of indoor-air volume in terms of energy saving.