• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6C
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• pp.231-239
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• 2010

This paper presents the thermal conduction analysis (using ABAQUS ver 6.10 and FLUENT ver 6.3.26) of geothermal energy for PHC, steel and copper energy piles by considering subsurface environment, thermal efficiency of grouting materials, and fluid velocity of circulating fluid. Results show that higher thermal efficiency for copper pile is observed followed by steel and PHC piles depending on the grouting materials and subsurface condition. The fluid velocity of 0.6m/s presents most efficient outflow temperature (275.4K) and heat exchange rate (103.1W/m) for the case of PHC pile during 8 hours operation. Analysis of operation schedule concludes that 16 hours of stand-by allows charging geothermal energy following 8 hours operation in winter season is most appropriate with 0.1K of temperature difference from the steady-state condition.

• Journal of Chest Surgery
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• v.23 no.1
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• pp.22-32
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• 1990

Postoperative cardiac performance of cyanotic congenital heart disease is somewhat different from that of other cardiac diseases. For the evaluation of postoperative cardiac performance in the cyanotic congenital heart disease we measured cardiac output by thermodilution technique at 1, 4, 8, 12, 16, 20, 24, 36, 48 postoperative hours in 14 patients operated from Feb. 1989 to Nov. 1989 in The Department of Thoracic and Cardiovascular Surgery, Seoul National University Children`s Hospital. At the same time, we checked left atrial pressure [LAP], central venous pressure [CUP], and mixed venous oxygen saturation [SvO2] to detect correlation between them. Immediate postoperative cardiac index was 3.585 $\pm$ 0.945 L/min/m2, and it decreased maximally to 3.322$\pm$1.007 L/min/m2 at postoperative 16 hours. After then it increased and stabilized from 36 hours after operation, and its value was 4.426$\pm$1.358 L/min/m2. There were no correlations between cardiac index and left atrial pressure or central venous pressure. Between mixed venous oxygen saturation and cardiac index, there was no correlation in the early postoperative period but after postoperative 16 hours, there was significant correlation between them and correlation coefficients were 0.573 [16hrs], 0.743 [20hrs], 0.436 [24hrs], 0.560 [36hrs], 0.636 [48hrs], respectively. From these results, we concluded that in the corrective surgery of cyanotic congenital heart disease, cardiac performance was depressed in the early postoperative period. It improved from postoperative 16 hours, and stabilized from 36 hours after operation. During early postoperative period, mixed venous oxygen saturation should not be used as a predictor of cardiac performance but it could be used as a predictor of cardiac performance from 16 hours after operation.

• Journal of Biosystems Engineering
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• v.36 no.6
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• pp.397-406
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• 2011

In this study, surveys on operation status of the 73 tractors with rated power of over 75 kW from six provinces in Korea were performed to obtain basic data required for development and efficient use of the high-power and high-performance tractors. And types of tractors and implements, operation crops, types of operations, annual operation areas, annual operation days, annual operation hours, operation speeds and widths, and problems and improvements in use were investigated. Most (91.7%) of the tractor surveyed were operated for forage and silage crops such as rice straw, whole barley, rye grass, reed canary grass, sudan grass, and the remains were operated for upland crops such as ginseng, sweet potato, potato, chinese cabbage, radish. Main operations of the tractors were cutting, baling, and wrapping for forage crops, plow tillage, rotary tillage, and manure spreading. About half (47.9%) of the tractors were used exclusively for forage crop harvesting such as forage crop cutting, forage baling, and bale wrapping, 24.5% of the tractors were used exclusively for plow or rotary tillage, and 27.4% of the tractors were used for both forage crop harvesting, and plow or rotary tillage. For the tractors with power ranges of 75~83, 89~94, 98~101, 113, 124 kW, average annual operation areas per tractor for plow tillage, rotary tillage, forage crop harvesting (cutting, baling, wrapping), and manure spreading operations were analyzed as 112.6. 144.8, 158.9. 390.0. 215.6 ha, respectively. and total average annual operation area per tractor was 171.3 ha. Average annual operation days per tractor for those operations were analyzed as 24.1, 28.9, 38.3, 55.4, 33.4, respectively, and total average annual operation days per tractor was 33.6. Average annual operation hours per tractor for them were analyzed as 260.0, 321.6, 408.1, 664.8, 413.8, respectively, and total average annual operation hours per tractor for the all tractors was 377.1. Ranges of operation widths of plow tillage, rotary tillage, forage crop cutting, forage baling, bale wrapping, and manure spreading operations were shown as 1.5~2.6, 2.3~3.0, 1.8~3.2, 1.8~2.0, 1.8~2.3, 3.1~6.6 m, respectively. Ranges of operation speed of plow tillage, rotary tillage, forage crop cutting, forage baling, bale wrapping, and manure spreading were shown as 6~9, 4~11, 9~16, 8~15, 8~17, 12~16 km/h, respectively.

• Journal of Chest Surgery
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• v.25 no.11
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• pp.1192-1202
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• 1992

Postoperative cardiac outputs and other hernoaynamic values were serially measured in fifteen patients of cyanotic congenital heart disease, after use of blood cardioplegic solution. Cardiac indices showed no change untill eight postoparative hours, then it began to decline to reach as low as 3.22$\pm$0.7L/min/m2 at 12 hours. After then gradual increse occ-ured to recover upto immediate postoperative value at 20 hours. Sharp decrese of heart rate and increse of systemic vascular resistance during 8~16 hours and steady increase of stroke indices during the whole study periods were observed. These observations suggested that the myocardium recovered gradually after open heart surgery, and that the decrease of cardiac indices during 8~16 hours could be a result of decrease of heart rates and increase of afterload. The changes of cardiac indices correlated with the changes of heart rate, postoperative time and mixed venous oxygen saturation [p<0.05]. No other hemodynamic values found to be in statistically significant correlation with the changes of cardiac indices. Left ventricular dysfunction seemed to occur more frequently during 8~12 hours, but it was not statistically significant. [p=0.73] In conclusion, great care must be taken during 2~3 days after the operation of cyanotic congenital heart disease, not to fall into a low cardiac output state, by maintaing adequate heart rates and reducing afterload especially when the systemic vascular resistance increases.

• Journal of Chest Surgery
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• v.33 no.10
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• pp.792-797
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• 2000

Background : Even though there were developments in various treatment techniques for acute arterial occlusion this disease still has high rate of mortalities and limb amputations. We investigated the combined diseases symptoms location of occlusion type of treatment complication and prognosis in our patients. Meterial and methods: This study recruited 48 patients(42 men, 6 women, mean age 57.7 years) who received the operation from January 1995 toDecember 1998. We investigated the post-operation course via medical record review or telephone interview with patients or their family members. Result: The most common combined diseases were atherosclerosis in 30 patients. other diseases were 17 diabetes mellitus 16 hypertension and 12 atrial firillation. Pain and clod sensation were noticed in all patients paresthesia in 5 patients fibrillation. Pain and cold sensation were noticed in all patients paresthesia in 5 patients and lower extremity paralysis in 11 patients. In 29 patients the time interval from the onset of symptom to admission was over 72 hours and 15 patients were admitted within 24 hours. The distribution of arterial occlusion location was at 28 femoral arteries 14 popliteal arteries and 6 iliac arteries. All the patients were received embolectomy and 5 patients were received additional bypass grafting. Postoperative complications were 12 reocclusions. 6 compartment syndromes 6 skin necrosis and 2 acute renal failure. The mortality rate was 16.7%(8/48) and the amputation rate was 25% Conclusion : This study revealed 25% reocclusion 25% limb amputation and 16.7% mortaliyt. To improve the prognosis of acute lower extrements arterial occlusion early diagnosis and understand the underlying diseases prompt treatment and operation additional operation including interventional radiologic examination and thorough postoperative care would be appreciated.

• Child Health Nursing Research
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• v.8 no.4
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• pp.400-413
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• 2002

The purpose of this study was to evaluate the effect of informational intervention on postoperative pain following tonsillectomy in children. This study was performed on 30 children, aged 5-15 years, undergoing tonsillectomy and their parents by providing informational intervention with colored figure; operation procedure and information. Pain assessment was done by Pain Questionnaire. The results from this study were as follows : 1. Children in experimental group with mean 16.07 had lower pain scores than control group with mean 14.87 at 4th hours after operation(p<0.05). It showed 'significant difference' and first hypothesis was adopted. 2. Children in experimental group with mean 20.60 had lower pain scores than control group with mean 17.27 at 8th hours after operation(p<0.05). It showed 'significant difference' and second hypothesis was adopted. 3. Children in experimental group with mean 28.80 had lower pain scores than control group with mean 25.70 at 24th hours after operation(p<0.05). It showed 'significant difference' and third hypothesis was adopted. 4. When we analyzed the time difference and difference between two groups simultaneously by repeated measure ANOVA, the significant difference was not found. And so 'the experiential group with operation-related information will show the lower pain sense than the control group just as the time flows after operation', fourth hypothesis was rejected. Generally, it was found that providing information about operation to children and their parents reduced effectively postoperative pain in children, but in clinical settings there are minimum preoperative information-providing because of insufficient time and inconvenience although nursing staffs and patients know its needs. Conclusionally providing preoperative information should help children and their parents cope with Pre, Peri and Post operative events effectively.

• Advances in pediatric surgery
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• v.7 no.1
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• pp.21-25
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• 2001

Congenital diaphragmatic hernia (CDH) in the past was considered a surgical emergency requiring immediate operation. Several groups now advocate preoperative stabilization and delayed surgery. The treatment strategy for CDH in this institution is delayed surgery after preoperative stabilization. The aim of this study was to evaluate the results of delayed surgery. A retrospective review of 16 neonates with CDH was performed. Surfactant. conventional mechanical ventilation. high frequency oscillation. and nitric oxide were utilized for preoperative stabilization as necessary. The difference in outcome between two groups differentiated by the duration of the preoperative stabilization periods with mechanical ventilation (${\leq}$ 8 hours and > 8 hours) was determined. Chi-square test was used to analyze the data. There were 7 right-sided hernias and 9 left. The average duration of stabilization was 32.4 hours. Hepatic herniation through the defect was found in 6 cases and all died. The most common postoperative complication was pneumothorax. The mortality rate of the right side hernia was higher than the left (85.7% vs. 33.3%. p=0.036). Mortality rate of the group (N=8) whose preoperative stabilization period was 8 hours or less was better than that (N=6) whose preoperative stabilization period was more than 8 hours (25.0% vs. 83.3%. p=0.031). The overall mortality rate was 56.3%. The better prognosis was noticed in left side hernia. no liver herniation, or shorter preoperative stabilization period.

• Journal of Korean Biological Nursing Science
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• v.16 no.3
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• pp.226-234
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• 2014

Purpose: This prospective study was designed to investigate the incidence of acute postoperative pain (APP) ${\geq}4$ and the risk factors of APP${\geq}$ for the first 48 hours after surgery. Methods: Data from 531 surgical patients were collected from November, 2009 to May, 2010. APP was assessed from the time of arrival at the Post Anesthetic Care Unit (PACU) to the end of the post-operative 48 hours. Risk factors of APP${\geq}$ were analyzed by logistic regression analysis. Results: The incidence of APP ${\geq}4$ was 58.8% for the first postoperative 4 hours; 33.5%, 24 hours; 11.1%, 48 hours. The score of pain was 5.55, the highest on arriving at PACU; 5.03 at postoperative 30 minutes; 4.03 at 1 hour; 3.96 at 4 hours; 2.76 at 24 hours; 1.44 at 48 hours Risk factors for APP ${\geq}4$ were females (Odds ratio [OR], 1.94; p=.013), general anesthesia (OR, 4.29; p<.001) and patient controlled analgesia (PCA) (OR, 2.83; p<.001) at 4 hours after operation; body mass index (BMI) ${\geq}25$ (OR, 1.80; p=.009), duration of surgery ${\geq}1$ hour (OR, 2.87; p=.037), general anesthesia (OR, 3.99; p<.001) and PCA (OR, 6.23; p<.001) at 24 hours; general anesthesia (OR, 3.53; p=.003) and PCA (OR, 3.01; p=.013) at 48 hours. Conclusion: Surgical patients with BMI ${\geq}25$, PCA and general anesthesia seem to have a higher incidence of pain ${\geq}4$ through the first postoperative 48 hours.

• Journal of Chest Surgery
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• v.27 no.8
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• pp.643-649
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• 1994

We evaluated sixteen patients of traumatic diaphragmatic injuries that we have experienced from Jan. 1987 to Aug 1993. Age was ranged from 6 to 71 years, predominantly in the fourth and fifth decades. 13 were male and 3 were female, a ratio of 4.3: 1. Blunt trauma was develped in 11 [Lt 7, Rt 4], penetrating trauma in 5 [Lt 2, Rt 3]. Preoperative diagnosis of diaphragmatic injury was possible in 8 patients [72.2 %] in blunt trauma, and 1 patient [20 %] in penetrating trauma. 8 cases[54.5%] in blunt trauma, and 4 cases in penetrating trauma were treated within 24 hours,meanwhile, patients treated after 10 days were 3, all by blunt trauma.The repair of 16 cases were performed with thoracic approach in 4 cases, thoracoabdominal approach in 3 cases, and abdominal approach in 9 cases. The herniated organs in thorax were stomach [5], colon [3], liver [2], and pancreas [1]. Postoperative complication were developed in 9cases[56.3%] significantly related with delayed operation time [p < 0.01 ]. Hospital mortality was 12.5 % [2/16], and the causes of death were hypovolemic shock in one and hepatic failure due to portal vein rupture in another.

• Journal of Chest Surgery
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• v.18 no.4
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• pp.753-758
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• 1985

Hemorrhage is an important complication after operation with cardiopulmonary bypass and sometimes necessitates a further emergency operation. Between July, 1962 and June, 1985, reoperation for hemorrhage was carried out on 81 patients [3.1%] out of a total 2634 patients who had previously undergone cardiopulmonary bypass surgery at the Department of Thoracic and Cardiovascular Surgery, Yonsei University Medical Center. There were 38 males and 43 females, with an average age of 25 years [ranging 6 months to 60 years] and an average body weight of 38 kg [ranging 5 to 77 kg].There were 43 patients of cyanotic heart disease, 32 patients of acquired valvular heart disease, 4 patients of coronary artery occlusive disease, 2 patients of ascending aorta aneurysm and annuloaortic ectasia. The average amount of blood loss in the case of cyanotic heart disease was 71.7140ml/kg, in acyanotic heart disease 45.16.3ml/kg, in acquired heart disease, 56.514.4ml/kg and in coronary artery occlusive disease, 50.618.7ml/kg during first post operative day. But there was no statistical difference [p>0.05]. The mean blood loss below 10 years old was 70.412.1 ml/kg. Those below 10 years old were believed to bleed more than any other group. But there was also no statistical difference [p>0.05]. Indications for reoperation were continued excessive blood loss [74%], cardiac tamponade or hypotension [23%] and radiological evidence of a large hematoma in the thorax and pericardium [2%]. Average bypass time was 2.10.1 hours [ranging 30 minutes to 5 hours]. The interval between operation and reoperation was as follows; less than 12 hours in 49 patients [60%], 12 to 24 hours in 20 patients [25%], 24 to 48 hours in 8 patients [10%], more than 48 hours in 4 patients [5%]. The commonest sites for bleeding were chest wall [36%], heart [34%], aorta [12%], pericardium [6%], thymus [5%] and others [6%]. But no definite source was found in ll patients [31%]. Twenty seven out of 81 patients [31%] had wound problems and 5 patients [6%] were expired. [Mean SEM]. In conclusion, in order to decrease the amount of blood loss after open heart surgery with cardiopulmonary bypass, shortening of bypass time and bleeding control at the wire suture site during chest wall closure were important. If the amount of blood loss was over 45 ml/kg or 8 m/kg/hour, reoperation should be considered as soon as possible. After operating, careful wound dressings were applied to prevent wound problems.