• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7227-7236
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• 2015

The survey revealed that, due to the discharge characteristics of seafood wastewater, irregular inflow loads were caused, making it difficult to treat the wastewater safely. It is crucial for the operation of pressure and floating tanks for the treatment of high-concentration organic wastewater such as seafood wastewater. The survey of operation factors for the pressure and floating tanks revealed this: A/S ratio 0.05 (design criteria 0.01), the pressurized air pressure 8bar(design criteria 6bar), the pressure tank pressure 6bar (design criteria 4.5bar), and HRT 60sec(design criteria: 10sec). Also, the recirculation rate was changed to over 40%(design criteria: 30%), and the surface load rate was changed to under $13.7m^3/m^2{\cdot}hr$(design criteria: under $17.7m^3/m^2{\cdot}hr$); thus, compared to the initial design criteria, the operation factors were changed according to inflow characteristics, thus enhancing the pressure and floating tank performance. The survey of inflow load revealed BOD 140.7%, $COD_{Mn}$ 120.32%, and SS 106.3%, compared to the inflow design criteria, as well as T-N 135.5% and T-P173.3%, higher than the design criteria. The survey of the treatment facility annual operation cost revealed high portions in sludge treatment cost(27.7%) and chemicals costs(26.0%), and the sludge treatment cost will likely further increase due to the ban on ocean dumping. The unit cost for the treatment of seafood wastewater was found to be KRW 3,858 per ton, more than 27 times higher than the sewage treatment cost(KRW 142.6/ton), presumably because the seafood wastewater contains high-concentration organic substances and nutritive salts.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.1 no.1
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• pp.3-17
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• 1998

The purposes of this study is to investigate the possibility of planting trees at space land in the riverside. The space land is for the green space. Calculating the plantable space in the representation section and the flood flowing stability of the existing banks based on the hydrological and meteorological data of the Kap-Chon riverbasin located in Tae-jon, the following results are drawn. (1) The flood discharges in each flow section are $698.7m^3/s$ in section 1, $654.6m^3/s$ in section 2, and $1353.3m^3/s$ in section 3 during 100 years recurrence interval. Because the designed-flood discharges in those sections are $1719.9m^3/s$, $2119.7m^3/s$, and $1512.8m^3/s$ respectively, safety for flood flowing is sufficient in existing banks. (2) The possible clearance for planting trees is 1.80m in section 1, 3.90m in section 2, and 0.01m in section 3. Planting clearance is enough in section 1 and 2. However, planting should be planned after estimating a rise-height due to the bridge piers, because many piers under riverine-highway are now on the construction in section 2. The section 3 does not have sufficient clearance for planting trees, but the planting is possible after getting enough flow area with slope by cutting the terrace land on the river artificially heightened. (3) In case of planting a tree 70cm diameter in $1m^2$ in section 1, the water level increases by 0.60m. Planting a tree in a $48m^2$ area increases the water level by 0.90m. Considering that plantable clearance is 1.8m in section 1, it is sufficient to flow safely. But if the trees are planted so compactly from the upper stream, expected heavy resistance is expected due to caught materials on the trees. So, trees have to be planted widely in upper streams but compactedly in lower streams. (4) The river width without changing, Kap-Chon's flow channel can be snaked in accordance with the nature law the wide terrace land in the riverside. Decreased flow area due to planting trees will be compensated by the inclination of terrace land. And, it is theoretically proved that the flood discharge is safe even though the terrace land on the river is parked similar to the nature. Planting trees in the terrace land of the Kap-chon river to the extent that flood flowing is not adversely affected, we can get the enjoyable park to citizens not spending expensive cost. It also contributes to the recovery of ecosystem, which gives the natural beauty of river and shade to citizens and becomes good natural-educational places for children.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.2
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• pp.183-193
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• 2018

Currently, the Korea Atomic Energy Research Institute (KAERI) is planning to build the Ki-Jang Research Reactor (KJRR) in Ki-Jang, Busan. It is important to safely dispose of low-level radioactive waste from the operation of the reactor. The most efficient way to treat radioactive waste is cement solidification. For a radioactive waste disposal facility, cement solidification is performed based on specific waste acceptance criteria such as compressive strength, free-standing water, immersion and leaching tests. Above all, the leaching test is important to final disposal. The leakage of radioactive waste such as $^{137}Cs$ causes not only regional problems but also serious global ones. The cement solidification method is simple, and cheaper than other solidification methods, but has a lower leaching resistance. Thus, this study was focused on the development of cement solidification for an enhancement of cesium leaching resistance. We used Zeolite and Loess to improve the cesium leaching resistance of KJRR cement solidification containing simulated KJRR liquid waste. Based on an SEM-EDS spectrum analysis, we confirmed that Zeolite and Loess successfully isolated KJRR cement solidification. A leaching test was carried out according to the ANS 16.1 test method. The ANS 16.1 test is performed to analyze cesium ion concentration in leachate of KJRR cement for 90 days. Thus, a leaching test was carried out using simulated KJRR liquid waste containing $3000mg{\cdot}L^{-1}$ of cesium for 90 days. KJRR cement solidification with Zeolite and Loess led to cesium leaching resistance values that were 27.90% and 21.08% higher than the control values. In addition, in several tests such as free-standing water, compressive strength, immersion, and leaching tests, all KJRR cement solidification met the waste acceptance or satisfied the waste acceptance criteria for final disposal.

• Journal of Chest Surgery
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• v.38 no.6 s.251
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• pp.428-433
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• 2005

Advanced age in Esophagectomy increases the risk of postoperative morbidity and mortality. However, the recent development of operative technique and perioperative care might have decreased the postoperative morbidity and mortality after esophagectomy. Material and Method: From March 2001 to July 2004, 174 patients underwent esophageal resection for esophageal cancer in the Center for Lung Cancer, National Cancer Center. The patients were divided into two groups : group 1 consisted of 27 patients aged 70 years or more, and group 2 consisted of 147 patients under 70 years of age. The two groups were compared according to preoperative risk factors, postoperative morbidity, operative mortality and survival. Result: The mean age was 63_4. There were 159 men. On histopathological examination, $93.1\%$ had squamous cell carcinoma. On the locations, $78.7\%$ were in mid and lower esophagus. Curative resections for esophageal cancer were possible in $162(93.1\%)$ patients. Mean hospital stay was 19.4 days with out difference between the groups. The overall postoperative morbidity were occurred in 61 patients $(35.1\%)$. The most frequent morbidity was pulmonary complication in $30(17.2\%)$. Preoperative incidence of hypertension, cardiac and pulmonary dysfunction were more common in Group I. However, there was no difference in overall postoperative morbidity, operative mortality and survival rate between the two groups. Conclusion: Esophagectomy for esophageal cancer could be carried out safely in patients over 70 years of age with satisfactory short-term results. Advanced age is no longer a risk factor for esophagectomy.

• Journal of Chest Surgery
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• v.34 no.12
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• pp.901-908
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• 2001

Background : Coronary artery bypass graft(CABG) in patients with advanced left ventricular dysfunction has often been regarded as having high mortality rate, despite the great improvement in operative result of CABG. With recent advances in surgical technique and myocardial protection, surgical revascularization improved the symptom and long-term survival of these high risk patients more than the medical conservative treatment. Material and Methold : Clinical data of 31(4.1％) patients with preoperative ejection fraction less than 30% among 864 CABGs performed between January 1995 and March 1999 were retrospectively analyzed and pre- and postoperative changes of the ejection fraction on echocardiography were analyzed. There were 26 men and 5 women. The mean age was 60.7 years(range 41 to 72 years). History of myocardial infarction(30 cases, 98％) was the most common preoperative risk factor. There were seven irreversible myocardial infarction on thallium scan. Most patients had triple vessel diseases(26 cases, 84％) and first degree of Rentrop classification(16 cases, 52％) on coronary angiography. The mean number of distal anastomosis during CABG was per patient was 4.9${\pm}$0.8 sites in each patient. In addition to long saphenous veins, the internal mammary artery was used in 20 patients. Total bypass time was 244.7${\pm}$3.7 minutes(range, 117 to 567 minutes), and mean aortic cross-clamp time was 77.9 ${\pm}$ 1.6 minutes(range, 30 to 178 minutes). There were five other reparative procedures such as two left ventricular aneurysrmectomy, two mitral repair, and one aortic valve replacement. There were twelve postoperative complications such as three cardiac arrhythmia, two bleeding(re-operation), one delayed sternal closure, eleven usage of intra-aortic balloon counterpulsation for low cardiac output. Two patients died, postoperative mortality was 6.5% . Twenty-nine patients were relieved of chest pain and left ventricular ejection fraction after operation was significantly higher(38.5${\pm}$11.6%, p 0.001) as compared with preoperative left ventricular ejection fraction(25.3${\pm}$2.3%). The follow up period of out patient was 25. 3 months. Conclusion: In patients with coronary artery disease and advanced left ventricular dysfunction, coronary artery bypass grafting can be performed relatively safely with improvement in left ventricular function, but it will be necessary to study long term results.

• Journal of Chest Surgery
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• v.40 no.1 s.270
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• pp.17-24
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• 2007

Background: The aim of this study is to assess the clinical results of various procedures in congenital aortic stenosis. Material and Method: From August 1987 to June 2004, 53 patients of congenital aortic stenosis underwent procedures such as percutaneous balloon valvuloplasty, aortic valvuloplasty, Ross procedure, and aortic valve replacement. The mean age of initial procedures was $8.2{\pm}6.0$ years. Percutaneous balloon valvuloplasty was peformed in sixteen patients, aortic valvulopiasty in thirty two patients, Ross procedure in nineteen patients, and aortic valve replacement in fourteen patients. The mean follow duration was $80.6{\pm}60\;(0{\sim}207)$ months. Result: There was 15.1% (8/53) of early mortality and no late mortality. The six patients with critical aortic stenosis were died of left ventricular dysfunction in early series (before 1 year; 4 cases) and two patients died after the Ross procedure and aortic valve replacement respectively. After percutaneous balloon valvuloplasty, most patients needed reoperations (14/16). Thirteen patients needed reoperation, after aortic valvuloplasty. After Ross procedure, two patients needed reoperation due to aortic regurgitation caused by progressive aortic root dilatation. The actuarial survival rate after Ross procedure at 7 years was 90.5%. Conclusion: In young children before the age of one, percutaneous balloon valvuloplasty was considered as :he safe initial palliative procedure. But children over one year-old, aortic valvuloplasty were the effective procedure. Ross procedure can be preformed safely with good results.

• Journal of Chest Surgery
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• v.42 no.6
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• pp.732-737
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• 2009

Background: Many video-assisted thoracic surgery (VATS) lobectomies are performed as a potential alternative to thoracotomy despite the controversy about the safety and the associated morbidity/mortality rates. Material and Method: Between November 2006 and August 2008, we performed 87 lobectomies (VATS 36, Thoracotomy 51) and we retrospectively reviewed the surgical treatment results. A VATS lobectomy was performed by a 4~5 cm thoracotomy without rib spreading and this included anatomic hilar dissection, individual vessel and bronchus stapling and lymph node dissection. Result: We studied 52 male and 35 female patients whose age ranged from 6 to 79 (average age: $59.8{\pm}15.0$ years). The cases were diagnosed with lung cancer (66) (SQC 24, ADC 38, others 4), pulmonary metastasis (2), carcinoid (2) and benign diseases (17). There was no intraoperative death. Postoperative complications were seen in 5 (15.6%) VATS and 33 (64.7%) thoracotomies, and perioperative death caused by adult respiratory distress syndrome occurred in 1 (2.8%) VATS and 3 (5.9%) thoracotomies. Three patients Underwent conversion to thoracotomy (8.3%). The mean time to chest tube removal was 6 days for VATS and 9.4 days for thoracotomy (p<0.001), and the mean length of the hospital stay was 8 days for VATS and 12.8 days for thoracotomy (p<0.001). Conclusion: VATS lobectomy can be performed safely with low morbidity/mortality rates. Furthermore, all the patients benefited from earlier postoperative rehabilitation and less pain and they were candidates for an earlier return to normal activities.

• Pediatric Infection and Vaccine
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• v.25 no.1
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• pp.35-44
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• 2018

Purpose: This study aimed to evaluate the immunogenicity and safety of a trivalent inactivated influenza vaccine (TIV) among healthy Korean children and adolescents. Methods: From October to December 2008, 65 healthy patients aged 6 months to 18 years who visited Korea University Ansan Hospital for influenza vaccination were enrolled in this study. We measured the hemagglutinin inhibition antibody titers at baseline and 30 days after vaccinating enrollees with split influenza vaccine and calculated the seroprotection rates, geometric mean titers, and seroconversion rates. Local and systemic adverse events were assessed after vaccination. Results: The seroprotection rates against all three viral strains (A/H1N1, A/H3N2, B) were 87.7%, 89.2%, and 89.2% (${\geq}70%$), respectively; seroconversion rates were 44.6%, 73.8%, and 63.1% (${\geq}40%$), respectively; and seroconversion factors were 4.5, 8.4, and 10.5 (>2.5), respectively. The TIV immunogenicity was acceptable according to the CPMP (Committee for Proprietary Medicinal Products) criteria. Although 48 patients (73.8%) reported one or more adverse events, no severe adverse events such as anaphylaxis and convulsion were observed. Forty-two patients (64.6%) reported a local skin reaction, including redness (29.2%), pain (43.1%), or swelling (41.5%) of the injected site, and 26 (40.0%) reported a systemic reaction: fatigue (23.1%), myalgia (20.0%), headache (10.8%), arthralgia (10.8%), chills (9.2%), or fever (7.7%). Conclusions: This study shows that the immunogenicity of the TIV vaccine is acceptable. As there were no serious adverse events aside from local reactions and mild systemic reactions, this vaccine can be safely used among healthy Korean children and adolescents.

• Journal of Preventive Medicine and Public Health
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• v.28 no.4 s.51
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• pp.795-807
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• 1995

This study was carried out from 1993 to 1994 in the small industries in Incheon. The objectives of this study was in order to estimate the quitting rate, to identify its relating factors and to propose effective quitting management policy in the small industries. The results were as follows ; 1. The quitting rate of 266 study workers was 42.1%(112 workers). 2. Age, working duration, position, marrital status were significant difference between the quitting group and the non - quitting group. In the quitting group, mean age was young, working duration was short, general employees and unmarried workers were many compared with the non - quitting group. 3. In the industry characteristics, total assets, total assets, sales per person, establishment duration and occupational health and safely status were significant difference between the quitting group and the non - quitting group. In the quitting group, total assets, total sales and sales per person were little, establishment duration of company was short and occupational health and safety status were poor compared with the non - quitting group. 4. In the quitting group, worker's response to employer's disposal about health and safety was more passive and the relation to employer with employee was significantly poor compared with the non - quitting group. 5. Multiple logistic regression analysis of quitting against family income per person, working duration, relation to employer with employee, occupational health and safety status in industry, worker's response to employer's disposal about health and safety and sales per person was done. Working duration, occupational health and safety status, worker's response to employer'1 disposal about health and safety were significant explainatory variables for quitting. Above results showed that the quitting rate was high and it was significant difference between the quitting group and non : quitting group according to characteristics of workers and of industries. Especially, it suggested that working duration, occupational health and safety status and worker's response to employer's disposal about health and safety were significant quitting factor. Therefore, it should be reflected in the quitting management and the policy of steady employment.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.962-968
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• 2002

Effects of gamma-irradiation of 1 to 10 kGy on the microbial growth, contents of amino acids, fatty acids, and free sugars, and changes in acid values in soybean powder were studied. Irradiation doses at $3{\sim}5\;kGy$ inhibited the mold growth completely in two kinds of imported soybean powders. Contents of sulfur-containing amino acids, such as cysteine, in both soybean powders decreased with irradiation, whereas no significant changes in free amino acid and fatty acid contents of both soybean powders were observed. Free sugar contents of stachyose and sucrose in Chinese soybean powder decreased with increasing irradiation dose level, whereas, those of other sugars remained unchanged. Results of this study confirm that $3{\sim}5\;kGy$ irradiation can be safely applied to apply to soybean powder without causing significant quality deteriorations microbiologically and chemically.