• Journal of Chest Surgery
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• v.30 no.3
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• pp.282-286
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• 1997

In the era of coronary artery bypass grafting, the intraaortic balloon pump (IABP) is more widely used and its indication has been ex anded. We perf'orbed retrospective clinical analysis on the patients who have received IABP pre andfor postoperatively during the course of CABG. From January 1981 to June 1995, total 322 patients have received CABG at the Seoul National University Hospital and among them 50 patients (15.5%) were supported by IABP during the course of the operation. The mean age at the time. of the operation was 57.2 years (39∼ 75 years) and the male to female ratio was 33 : 17. The preoperative diagnosis was unstable angina in 33 (66%), stable angina in 7 (14%) and postinfarct angina in 8 patients(16%). As for the indications of the IABP, there were 13 cases(26%) with left main disease, 13 (26%) with class IV angina, 12 (24%) with difficulty in CPB weaning, 6 (12%) with postinfarct angina and 3 (6%) with severe LV dysfunction. In the remaining 3 cases, one patient was operated on after PTCA failure in emergency basis, another was a patient with AMI, and the other was one who had postoperative low c rdiac output syndrome. All IABPS were introduced via femoral artery and among them 45 cases (90%) percutaneously. The mean postoperative assist time was 22.3 hours (0.5 ∼ 168 hours) and IABP could be removed within 48 hours in most of them (44150). The operative mortality was 6.1% (3 cases) and postoperative morbidity was only one with lower extremity ischemia. The more general application of the IABP during the course of the CABG ,especially in patients with high preoperative risk factors or difficulty in CPB weaning is a good measure of protecting and recovering myocardial function with minimal risk.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.2
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• pp.58-72
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• 2018

Ganghwa has met a new development period in land use and infrastructure based on the 4th National Development Planning, however the public transportation system is not systematically operated yet. This paper analyzes the bus trip pattern in Ganghwa using transportation card data during a week. The result indicates that average 7,100 people use buses a day and the most frequent use occurred in Friday. Clear peak-hours between 7 and 8 A.M. and between 4 and 5 P.M. were appeared due to commuting and school trips. According the result of regression analysis, population and the number of hospitals and schools area showed positive relationships with but trips reflecting regional characteristics. The research contributes to providing basic data for constructing an efficient public transportation system in the future.

• Journal of Chest Surgery
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• v.38 no.4 s.249
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• pp.277-283
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• 2005

Arterial oxygen saturation $(SaO_2)$ instability frequently takes place after systemic-pulmonary shunt without shunt occlusion. We analyzed actual incidence and risk factors for $SaO_2$ instability after shunt operations, and possible mechanisms were speculated on. Material and Method: Ninety three patients, who underwent modified Blalock-Taussig shunt from January 1996 to December 2000, were enrolled in this study. Adequacy of shunt was verified in all patients, either by ensuing one ventricle or biventricular repair later on or by appropriate pulmonary artery growth on postoperative angiogram. Age, body weight, hemoglobin level at operation were 3 day to 36 years (median: 1.8 months), 2.5kg to 51kg (median: 4.1kg) and $10.7\~24.3$ gm/dL (median: 15.2 gm/dL) respectively. Preoperative diagnoses were functional single ventricle with pulmonary stenosis or atresia in 39, tetralogy of Fallot in 38 and pulmonary atresia with intact ventricular septum in 16. Pulmonary blood flow (PBF) was maintained pre-operatively by patent ductus or previous shunt in 64 and by forward flow through stenotic right ventricular outflow tract (RVOT) in 29. $SaO_2$ instability was defined as $SaO_2$ less than $50\%$ for more than 1 hour with neither anatomic obstruction of shunt nor respiratory problem. Result: 10 patients $(10.7\%)$ showed $SaO_2$ instability after shunt operation. After shunt occlusion was ruled out by echocardiogram, they received measures to lower pulmonary vascular resistance (PVR), which worked within a few hours in all patients. Risk factors for $SaO_2$ instability included older age at operation (p=0.039), lower preoperative $SaO_2$ (p=0.0001) and emergency operation (p=0.001). PBF through stenotic RVOT showed marginal statistical significance (p=0.065). Conclusion: $SaO_2$ instability occurs frequently after shunt operation, especially in patients with severe hypoxia pre-operatively or unstable clinical condition necessitating emergency operation. Temporary elevation of pulmonary vascular resistance is a possible mechanism in this specific clinical setting.

• Advances in pediatric surgery
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• v.17 no.2
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• pp.133-138
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• 2011

Extracorporeal membrane oxygenation (ECMO) has been utilized in congenital diaphragmatic hernia (CDH) patients with severe respiratory failure unresponsive to conventional medical treatment. We retrospectively reviewed 12 CDH patients who were treated using ECMO in our center between April 2008 and February 2011. The pre ECMO and on ECMO variables analyzed included gestational age, sex, birth weight, age at the time of ECMO cannulation, arterial blood gas analysis results, CDH location, timing of CDH repair operation, complications and survival. There were 9 boys and 3 girls. All patients were prenatally diagnosed. Mean gestational age was $38.8{\pm}1.7$ weeks and mean birth weight was $3031{\pm}499$ gram. Mean age at the time of ECMO cannulation was $29.9{\pm}28.9$ hours. There were 4 patients who survived. Survivors showed higher 5 min Apgar scores ($8.25{\pm}0.96$ vs. $7.00{\pm}1.20$, p=0.109), higher pre ECMO mean pH ($7.258 {\pm}0.830$ vs. $7.159{\pm}0.986$, p=0.073) and lower pre ECMO $PaCO_2$ ($48.2{\pm}7.9$ vs. $64.8{\pm}16.1$, p=0.109) without statistical significance. The hernia was located on the left side in 10 patients and the right side in 2 patients. The time interval from ECMO placement to operative repair was about 3~4 days in 5 early cases and around 24 in the remaining cases. There were 3 cases of post operative bleeding requiring re operation and 2 cases of abdominal compartment syndrome requiring abdominal fascia reopening. ECMO catheter reposition was required in 4 cases. Three cases of arterial or venous thrombosis were detected and improved with follow up. Our data suggests that ECMO therapy could save the lives of some neonates with CDH who can not be maintained on other treatment modalities. Protocolized management and accumulation of case experience might be valuable in improving outcomes for neonates with CDH treated with ECMO.

• Journal of Korean Home Economics Education Association
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• v.15 no.3
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• pp.29-44
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• 2003

This study aimed to evaluate the subject matters and goals, and to know the operation of Technology·Home Economics of middle and high schools in Kyungnam area. Data were collected from 235 teachers with the questionnaire by mail. The results were following; 1. The major of teachers was Technology·Industry 30.6%, Home Economics 67.2%. The teaching style was the team-teaching 51.1%, one's responsible teaching 41.3%. The team-teaching was operated more frequently in high schools than middle schools. The most difficulties were the shortage of subject's hours, the shortage of practice hours, etc. 2. The overall evaluation of subject's matters and goals were about middle levels. but the items of the job-course education and the interrelatedness of Technology and Home Economics were a little low levels. 3. The speciality and the utility of the subject's matters were evaluated highly oneself for one's major, but those of different major were lowly so. The sector of Computer was shared commonly with Technology and Home Economics' teachers. 4. The attitudes toward the separation or integration of Technology·Home Economics in the 8th curriculum revision were half and half. If Technology·Home Economics will be separated, each subject need 2 hours per week.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.2
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• pp.74-80
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• 2008

Removal of nitrogen compound under nitrification related with denitrification by biofilm which developed on the porous media was investigated. With the investigation of $NH_4-N$ nitrification and autotrophic denitrification supplied with sulfur media as electron donor, conclusions were retrieved as follows. When $F/M_N$ ratio of $NH_4-N$ was increased from $0.0062-0.034gNH_4-N/g\;MLVSS{\cdot}day$ by the change of influent concentration and HRT the nitrification rate decreased as the increase of loading rate. Also under the same conditions of $F/M_N$ ratio, the alkalinity consumption rate of operation was higher at 8 hours of HRT than at 6 hours of HRT. Accordingly the influent loading rate variation by detention time with influent flow influenced more on the nitrification efficiency than the influent loading rate variation by the influent concentration did. Denitrification rate with various EBCT(Empty Bed Contact Time) showed average 25% at 8.4hrs of EBCT but sharply decreased average 5% at 4.6hrs of EBCT, so the operation would be more effective at above 8.4hrs of EBCT. Also denitrification rate was known to be adversely increased as $NO_3-N$ loading rate per unit volume of sulfur-media was decreased within the range of $0.5{\sim}2.0kgNO_3-N/m^3{\cdot}day$.

• Progress in Superconductivity and Cryogenics
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• v.19 no.1
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• pp.13-16
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• 2017

Water issue, especially water pollution, is a serious issue of 21st century. Being an significant technique for securing water resources, superconducting magnetic separation wastewater system was indispensable. A large bore conduction-cooled magnet was custom-tailored for wastewater treatment. The superconducting magnet has been designed, fabricated and tested. The superconducting magnet was composed of NbTi solenoid coils with an effective horizontal warm bore of 400 mm and a maximum central field of 2.56T. The superconducting magnet system was cooled by a two-stage 1.5W 4K GM cryocooler. The NbTi solenoid coils were wound around an aluminum former that is thermally connected to the second stage cold head of the cryocooler through a conductive copper link. The temperature distribution along the conductive link was measured during the cool-down process as well as at steady state. The magnet was cooled down to 4.8K in approximately 65 hours. The test of the magnetic field and quench analysis has been performed to verify the safe operation for the magnet system. Experimental results show that the superconducting magnet reached the designed magnetic performance.

• Journal of Chest Surgery
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• v.25 no.3
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• pp.220-231
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• 1992

We have performed 28 single lung transplantation in mongrel dogs transplanting the left lung exclusively from November 1989 to September 1991, in the department of thoracic surgery of Seoul National University Hospital. In the donor dogs, the main pulmonary artery was divided proximal to its bifurcation, and the left atrium was incised freeing the left veins with a generous atrial cuff. We used cold saline in the first 7 transplantations and Euro-Collins or modified Euro-Collins solution in the remaining 17 transplantations as a lung preservatives. The bronchus was divided at two cartilage rings proximal to the upper lobe bronchus take off. In the recipient procedure, we used a Fogarty catheter as a bronchus block. Left atrial anastomosis was performed first using 5-O prolene and the pulmonary artery was anastomosed using 6-O prolene. The bronchus was anastomosed next with 4-O vicryl interruptedly and covered with a greater omentum which had been prepared previously. All dogs received cyclosporin A and azathioprine as immunosuppressants and were divided into two group. In the 10 Group I dogs, they survived within 6 days, mean survival time was 66.8$\pm$53.4 hours. In remainder 14 Group lI dogs, they survived above 6 days, mean survival time was 9. 5$\pm$5.6 days. The cause of death were as follows: 2 cases of sacrifice, 2 cases of respiratory insufficiency during operation, 2 cases of arrhythmia immediate postoperatively, 2 cases of bleeding, others in Group I, and 6 cases of sacrifice, 4 cases of sepsis, 3 cases of bleeding, others in Group lI. Results of bronchoscopic findings were obstruction above 50% in 12 cases of 16 performance cases within 5th day. Early chest radiologic haziness were showed, and total lung perfusion defect was frequently showed in both group within 7th day. Main autopsy findings were left atrial and pulmonary arterial thrombi and bronchial obstruction The major histologic findings of Group I were pleural exudate, hemorrhagic infarct, pulmonary congestion, and interesting histologic findings of Group II were 3 cases of perivascular or peribronchial lymphocyte infiltration, 3 cases of hemorrhage infarct, 2 cases of interstitial pneumonitis. The structual change of bronchioles, suggesting bronchiolitis obliterans was not observed due to improper preparation of proximal pulmonary tissue and short term survival times.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.6
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• pp.734-744
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• 2013

In this study, the telematics device was installed on the car (OBD-II) to collect the information on the operation conditions from each sample vehicle. Based on the information the domestic driving pattern was analysed and the ratio of cold start length was estimated. As a result of analysis for driving pattern, we found a difference in the frequency of driving on the hourly or seasonal basis. Then, the driving pattern of the rush hours, weekdays, and weekends could be derived. Also, from the study, an average of 2.22 times per day occurred in a single trip and average driving distance for the trip was 15.72 km. In addition, the proportion of cold start length was analyzed to be 16.11%. The seasonal cold start length has big difference from season to season (Winter 26.63%, Summer 8.22%, Intermediate 12.65%). There was an inverse relationship between the outside temperature and ratio of cold start length. In order to improve the accuracy of the cold emission estimation, it is necessary to apply domestic ratio of cold start length that driving pattern and temperature in Korea is reflected.

• Archives of Plastic Surgery
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• v.41 no.5
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• pp.486-492
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• 2014

Background We conducted this study to identify the correlation between the time to surgery and that to recovery from postoperative diplopia. Methods In the current single-center, retrospective study, we enrolled a total of 11 patients (n=11) who were diagnosed with white-eyed blowout fracture and underwent surgical operation at our institution between January 2009 and January 2013. To identify the correlation between the time to surgery and that to recovery from postoperative diplopia, we divided our patients into the three groups: the group A (time to surgery, <2 days) (n=4), the group B (time to surgery, 3-7 days) (n=4) and the group C (n=3) (time to surgery, 8-60 days). Then, we compared such variables as sex, age, signs of soft tissue injury, preoperative nausea/vomiting, the degree of preoperative diplopia and the side of the fracture on computed tomography scans between the three groups. Results In our series, mean age at the onset of trauma was nine years (range, 5-16 years); the mean time to surgery was 30 days (range, 2-60 days); and the mean follow-up period was one year (range, 6 months-2 years). Our results showed that the time to recovery was shorter in the patients with a shorter time to surgery. Conclusions We found that the degree of recovery from impaired ocular motility and diplopia was the highest in the patients undergoing surgical operations within 48 hours of the onset of trauma with the reconstruction of the fracture sites using implant materials.