• Journal of Environmental Science International
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• v.3 no.4
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• pp.417-425
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• 1994

Leachate from municipal landfill site is known to be hard to treat because it commonly contains various toxic material and heavy metals. In addition, portions of biodegradable organic substances in leachate are decreasing in the course of wastes stabilization, which is one of the critical reason for inefficient biological treatment at the end stage of landfill site operation. So this study was conducted to examine the feasibility of municipal lanuill leachate pretreatment using electrolysis. The optimum electrode combination was made. The optimum electrode combination was found to be lead and graphite.

• The Journal of the Korean dental association
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• v.33 no.4 s.311
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• pp.264-273
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• 1995

2000년대에 있어서 세계의학계는 인공심장의 완성과 인공신장, 인공 간, 인공수족과 인공골, 관절, 혈관 등의 인공장기이식의 눈부신 연구, 발전에 의하여 인간의 수명은 더욱 연장될 것이며 사망률을 낮추는 치료의학은 한없이 발전하게 될 것이다. 치과의학의 과제는 상실된 치아와 악골, 구강내외 장기의 수복을 위한 인공치아 및 장기이식의 치료요법의 발전이 될 것이다. 인공치아 치료요법의 한가지인 nonsubmerged and one stage operation type인 I.T.I. 임프란트 시스템은 골성접착과 결합이 이루어지는 인공치아 이식술로서 그 단순한 시술과 높은 성공률에 의해 전세계에 각광을 받는 치료방법의 하나이다.

• Journal of Chest Surgery
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• v.23 no.3
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• pp.546-549
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• 1990

Spontaneous esophageal perforation occurred rarely but often lead to a high mortality and morbidity. We had experienced one case of spontaneous rupture of esophagus. A 52 - year old male patient was admitted to our hospital because of the chest pain and massive hematemesis after emetic strain. Esophagogram that taken at private clinic revealed leakage of dye into the right pleural space. Under the diagnosis of the thoracic esophageal perforation, two stage operation was planned because the size of perforation was large and pyothorax was developed on the right side. At first, exclusion and diversion of the esophagus were carried out. After six months, the esophageal reconstruction with left colon was performed.

• Journal of Chest Surgery
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• v.37 no.4
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• pp.313-321
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• 2004

Excellent clinical results of the arterial switch operation and the limited availablity of the intraventricular rerouting has recently made an arterial switch operation to become the therapeutic method of choice for the repair of double-outlet right ventricle (DORV) with subpulmonary ventricular septal defect (VSD). The early and midterm outcomes of arterial switch operation for this anomaly were evaluated. Material and Method: Between August 1994 and July 2002, 13 patients underwent an arterial switch operation for the correction of double-outlet right ventricle with subpulmonary VSD at Dong-A university hospital.. The 50% rule was used to define DORV. Median age and mean body weight were 27 days (range, 3-120 days) and 3.8$\pm$0.7kg (range, 2.92-5.3kg) respectively. Aortic arch anomalies were associated in 6 cases (46.2%), which were all repaired through one-stage operation. The relationship of the great arteries were side-by-side in 8 cases (61.5%) and anteroposterior in 5 (38.5%). Coronary artery patterns were 1 LCx-2R in 6 cases, retropulmonary left coronary artery (LCA) in 6, and intramural LCA in 1 respectively. The enlargement of VSD was required in 1 patient and the patch enlargement of right ventricular outflow tract was performed in another one patient. The Lecompte maneuver was used in all but 3 patients with a side by side relationship of the great arteries. Result: Overall postoperative hospital mortality was 23.1 % (3/13). All operative deaths were occurred in the patients with aortic arch anomalies. There was one late death related to the postoperative complication of the central nerve system during the mean follow-up of 41.3$\pm$30.7 months. Pulmonary valvar stenosis (＞30mmHg of pressure gradient) developed in 1 patient (10%) and left pulmonary artery stenosis in 2 (20%), among them, one required reoperation 52 months after repair. There was an asymptomatic patient with moderate aortic regurgitation. 5-year survival rate including operative deaths was 68.3%. Conclusion: Although the operative mortality is high in the patients with aortic arch anomaly, the arterial switch operation for DORV with supbpulmonary VSD can be performed with low operative mortality and low reoperation rate in the patients Without arch anomaly. The arterial switch operation can be considered a good option for this complex anomaly.

• Journal of Chest Surgery
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• v.18 no.3
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• pp.506-512
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• 1985

We have experienced 120 non-small cell primary carcinomas of the lung between June, 1974 and December, 1984, at Seoul National University Hospital. They were 107 males and 13 females. 95% of all were ranged from 40 years to 69 years of age with 56 years of mean age. They were composed of 70 [66.7%] squamous cell ca., 20 [19%] adenoca., 6 [5.7%] undifferentiated large cell ca., 4 [3.8%] undifferentiated small cell ca., and 5 [4.8%] mixed adenosquamous cell ca. 41 [36%] and 35 [30.7%] patients have received pneumonectomies and lobectomies with a 66.7% resectability rate. Of the 36 stage I and 21 stage II patients, 56 were resectable but only 20 [31.7%] of the 63 stage III patients were resectable. This informed us the significance of the stage of the disease at the time of operation. The actuarial survival rate in 70 patients was as follow: 1, 3, 5 year survival rate of the patients in stage I were 80%, 80%, and 60% respectively. Both 1, 3 year survival rate of patients in stage II were 84%. But 1, 2, 3 year survival rate of patients in stage III were 40%, 11%, and 5% respectively. By dividing the patients in stage III into resectable group and nonresectable one, both 1, 2 year survival rate of the former were 37% and those of the latter were 42% and 7%. According to the cell type of the cancer, 1, 3, 5 year survival rate of the squamous cell ca. were 63%, 40%, and 26% respectively. 1, 3 year survival rate of the adenoca. were 43% and 34%. Hospital death were only 2 cases with a 1.7% operative mortality rate. We had acceptable long-term survival rate and have convinced the necessity and hope of the early detection and resection of the lung carcinoma.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.771-777
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• 2012

This paper proposes a binary arithmetic encoder of CABAC using a Common Operation Unit including the three modes. The binary arithmetic encoder performing arithmetic encoding and renormalizer can be simply implemented into a hardware architecture since the COU is used regardless of the modes. The proposed binary arithmetic encoder of CABAC includes Context RAM, Context Updater, Common Operation Unit and Bit-Gen. The architecture consists of 4-stage pipeline operating one symbol for each clock cycle. The area of proposed binary arithmetic encoder of CABAC is reduced up to 47%, the performance of proposed binary arithmetic encoder of CABAC is 19% higher than the previous architecture.

• Transactions on Electrical and Electronic Materials
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• v.10 no.2
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• pp.44-48
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• 2009

A simulation study of a 10-bit two-stage DAC was done by using a conventional current switch cell. The DAC adopts the segmented architecture in order to reduce the circuit complexity and the die area. The 10-bit CMOS DAC was designed in 2 blocks, a unary cell matrix for 6 MSBs and a binary weighted array for 4 LSBs, for fabrication in a 0.35-${\mu}m$ CMOS process. To cancel the accumulation of errors in each current cell, a symmetrical switching sequence is applied in the unary cell matrix for 6 MSBs. To ensure high-speed operation, a decoding circuit with one stage latch and a cascode current source were developed. Simulations show that the maximum power consumption of the 10-bit DAC is 74 mW with a sampling frequency of 100 MHz.

• Journal of environmental and Sanitary engineering
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• v.13 no.2
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• pp.57-65
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• 1998

In this research, Effect of C/N ratio on nutrient removal in intermittently aerated activated sludge system(IAASS) was investigated with dormitary, building and swine wastewater. Three types (2-stage, 4-stage, modified) of IAASS were operated. Time interval of aeration/nonaeration in IAASS was 1hr/1hr. In treatment of Dormitary wastewater(BOD/T-N ratio : 4.4), Building wastewater (BOD/T-N ratio : 3.14) and swine wastewater(BOD/T-N ratio : 3.84), Nitrogen removal efficiency of 80, 70 and 90.4% was achieved, respectively. Nitrogen removal in IAASS was a great influenced on influent C/N ratio, efficient nitrogen removal was achieved at BOD/T-N ratio over 4. In IAASS operation, $\Delta $BOD mg/L/$\Delta $ nitrogen mg/L ratio was about 4-6. Simultaneous removal of organic, nitrogen and phosphorus in IAASS can achieved. And influent organic was efficiently utilized in denitrification. IAASS could be one of the best alternative process for the retrofit of conventional activated sludge system for the removal of nutrients.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.2205-2210
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• 2003

The 1st stage bucket of the 170MW simple cycle gas turbine is one of the components that is normally run in exposed state at the highest thermally stressful environment while the turbine is operating. After certain period operation, various type of damages are easily found and the damages are identified as due to the turbine operating mode of which the demand of the electricity power is very peaking and cyclic. Since this trend is more evident at some part of power plants in Korea and it has caused higher scrap rate of the bucket at the first repair interval than other country. Therefore, demand for the higher capability and alternative technologies which allow salvaging more buckets and preventing from severe damages is always high. In this study, a review and estimation of the repair technologies for the past 5 years to present have been conducted and show results.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.694-700
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• 1998

A novel zero-voltage-transition (ZVT) isolated PWM boost converter for single stage power factor correction (PFC) is presented to improve the performance of the previously presented ZVT converter[8]. A simple auxiliary circuit which includes only one active switch provides zero-voltage-switching (ZVS) condition to all semiconductor devices. (Two active switches are required for the previous ZVT converter) This leads to reduced cost and simplified control circuit comparing to the previous ZVT converter. The ZVS is achieved for wide line and load ranges with minimum device voltage and current stresses. Operation principle, control strategy and features of the proposed converter are presented and verified by the experimental results from a 1.5 kW, 100 KHz laboratory prototype.