• Journal of Yeungnam Medical Science
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• v.9 no.2
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• pp.321-326
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• 1992

The study consisted of all patients over 35years old undergoing surgical repair of atrial septal defect for the period from June 1985, to August 1992. The following results were observed. 1. ASD was closed with patch in 11(73%) patients. 2. The relationship of pulmonary artery systolic pressure to Qp/Qs ratio was not significant. 3. Before operation 6 patients were in NYHA functional class II, 8 were in class III, After operation 8 patients were in class I, 6 were in class II. 4. Atrial fibrillation has persisted in 3 patients and returned regular rhythm in 1 patient after surgery. 5. There was no operative mortality and we had good surgical results regardless of patient's age.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8C
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• pp.591-597
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• 2008

In this paper, we present a improved rate distortion optimization (RDO) for H.264 intra coding. By using new mode decision criteria pass for $I4{\times}4$ in company with the original RDO, the proposed method can achieve the better coding efficiency comparing with the original RDO. Our experimental results show that the proposed algorithm can archive about $0.64{\sim}1.6578%$ bit rate decrease at the same PSNR and $0.049{\sim}0.101dB$ PSNR increase at the same bit rate.

• Journal of Chest Surgery
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• v.23 no.5
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• pp.962-967
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• 1990

The anomalous pulmonary venous return of the entire left lung was an extremely rare congenital anomaly. The reported surgical experience with correction of this disorder was limited. The 3-year-old female patient underwent an operation upon the unilateral total anomalous pulmonary venous return from the left lung, in which the left superior pulmonary vein drained into innominate vein and the left inferior pulmonary vein into the coronary sinus, in Yeungnam University Hospital. The symptoms were nonspecific except frequent upper respiratory infection. Cyanosis was not seen. On auscultatory findings, a grade 2/6 systolic ejection murmur was audible over left second intercostal space of left sternal border and second heart sound had an increased pulmonary component which was widely splitted. The electrocardiogram demonstrated a right ventricular hypertrophy and right axis deviation and chest X-ray showed slightly increased pulmonary vascularity and bulged pulmonary conus. The echocardiogram demonstrated increased right atrial, ventricular, and pulmonary arterial dimension, and also secundum atrial septal defect and enlarged coronary sinus. The cardiac catheterization confirmed the left-to-right with a Qp/Qs of 2.0: 1 and oxygen step-up was seen in pulmonary artery, right ventricle, right atrium, and left innominate vein, and the catheter was not been introduced into the left pulmonary vein. A median sternotomy incision was done. Left superior pulmonary vein was drained to the innominate vein through anomalous vertical vein and the left inferior pulmonary vein drained to right atrium through the coronary sinus. The diversion of the left inferior pulmonary vein to posterior wall of left atrium was done after division in the proximity of coronary sinus. The anomalous vertical vein was diverted to base of left atrial auricle and then a atrial septal defect was sutured directly. The postoperative course was uneventful and she was discharged on the eleventh postoperative day. In the postoperative follow-up-2 months, she has been well without specific problems.

• Journal of Chest Surgery
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• v.28 no.2
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• pp.136-142
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• 1995

A clinical study was performed on 69 cases of isolated PDA surgically treated at the Department of Thoracic and Cardiovascular surgery of Kyung-Hee University Hospital from Mar. 1986 to Feb. 1994. Retrospective clinical analysis of these patients were as follows: 1.23 males and 46 females ranged in age from 16 days to 49 years. [mean 8.69yrs.,sex ratio M:F=1:2 2. Chief complaints were frequent URI in 44%, dyspnea on exertion in 16%,palpitation in 8%, easy fatigability in 6%, and no subjective symptoms in 26%. 3. On auscultation, typical continuous machinery murmur heard in 84%, and systolic murmur in 16% on Lt 2nd or 3rd intercostal space. 4. Simple chest x- ray showed increased pulmonary vascularity in 67%, cardiomegaly in 61%,and within normal limit in 16%. 5. EKG findings were LVH in 42%, biventricular hypertrophy in 17%, RVH in 3%, and within normal limit in 38%. 6. Echocardiogram was performed from all patient, and direct visualization of ductus in 93% 7. Cardiac catheterization was performed in 39 patients. The mean value of the results were;Differance SaO2[MPA-RV =11.03$\pm$ 5.26%,Qp/Qs=2.44$\pm$1.35,systolic pulmonary arterial pressure=40.69 $\pm$ 17.69mmHg. 8. 66 patients were operated through the left posterolateral thoracoctomy ; closure of ductus by double ligation in 43 cases, triple ligation in 23 cases.3 patients were operated by simple closure under cardiopulmonary bypass. 9. There was no death associated with the operation. The operative complications were atelectasis in 8 cases, pneumonia in 4 cases recannalization in 2 cases, and hoarseness in one case. 10. Systemic diastolic pressure was increased 8.12$\pm$ 0.13mmHg, and pulse pressure was decreased about 9.52 $\pm$ 1.87mmHg.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.81.1-81.1
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• 2011

The new coherent scatter ionospheric radar has been operating at Gyerong city ($36.18^{\circ}N$, $127.14^{\circ}E$, dip lat $26.7^{\circ}N$), South Korea. This VHF radar is consisted of 24 Yagi antennas having 5 elements and observes the E- and F-region field-aligned irregularities (FAIs) in a single frequency of 40.8 MHz with a peak power of 24 kW. We present the first results of the E- and F-region FAIs over Korea by using the new VHF coherent scatter ionospheric radar. The morphological and echo characteristics are studied in terms of their echo strength, Doppler velocity and also by spectral width values. From the continuous observations from December 2009, we found ionospheric E- and F-region FAIs appeared frequently. The most interesting and striking observations for E region are occurrence of daytime E-region irregularities and strong Quasi-Periodic (QP) echoes at nighttime. And for F region, strong post-sunset and pre-sunrise FAIs appeared frequently. The VHF radar observations over Korea are discussed in the light of current understanding of mid-latitude E- and F-region FAIs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.7B
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• pp.538-549
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• 2008

Recently IEEE 802.22 WG has considered Cognitive Radio (CR) technology to overcome shortage of communication channels. For using CR technology, accurate and rapid sensing method selection is extremely important. According to the channel sensing method, it is of the utmost importance because it can affect the incumbent system protection. So, optimum selection of channel sensing method is very important. IEEE 802.22 gives the solution, name of fine sensing, but the solution can not adapt to various networks. So in this paper we propose Policy-based Channel Sensing Architecture and Algorithms for Cognitive Radio Networks. The proposed channel sensing architecture and algorithms can reduce both primary system detection time and quiet time in our simulation. Among the proposed sensing algorithm, channel division round robin sensing reduce average detection time up to 70% compare to fine sensing method in IEEE 802.22.

• Microbiology and Biotechnology Letters
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• v.19 no.3
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• pp.272-280
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• 1991

The effect of media feeding rate on cell growth and monoclonal antibody production in the fed-batch culture ot hybridoma A4W was studied. In the batch culture, the highest specific antibody production rate was observed at the begining of the culture period but its value tended to decrease rapidly with the culture time. The final antibody concentration and volumetric productivity was 65 $\mu g$/ml and 13 mg Mab/l/day, respectively. In the fed-batch culture, the specific antibody production rate, $q_p$ rebounded sharply within a few hours after the media feeding was started and it remained high until the end of culture if the media feeding was continued. The final antibody concentration was 220 $\mu g$/ml and the volumetric productivity was 45.1 mg/l/day. Further increase in final antibody concentration was achieved by applying a modified media of which component was fortified with glucose and glutamine, hence the final antibody concentration in this case was 270 $\mu g$/ml and the volumetric productivity was 51.8 mg/lday, which is as four tinlcs as high cuixparinf! to that of batch culture.

• Journal of Electrical Engineering and Technology
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• v.8 no.2
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• pp.326-330
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• 2013

The Korea Superconducting Tokamak Advanced Research (KSTAR) device is an advanced superconducting tokamak to establish scientific and technological bases for attractive fusion reactor. This device requires 3.5 Tesla of toroidal field (TF) for plasma confinement, and requires a strong poloidal flux swing to generate an inductive voltage to produce and sustain the tokamak plasma. KSTAR was originally designed to have 16 serially connected TF magnets for which the nominal current rating is 35.2 kA. KSTAR also has 7 pairs of poloidal field (PF) coils that are driven to 1 MA/sec for generation of the tokamak plasma according to the operation scenarios. The KSTAR Magnet Power Supply (MPS) was dedicated to the superconducting (SC) coil commissioning and $2^{nd}$ plasma experiment as a part of the system commissioning. This paper will describe key features of KSTAR MPS for the $2^{nd}$ plasma experiment, and will also report the engineering and commissioning results of the magnet power supplies.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.1
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• pp.64-74
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• 2008

It is well-known that the coding efficiency of CABAC which is one of the entropy coding methods in H.264/AVC is lower than that of CAVLC at high bitrate in intra coding, even if CABAC shows higher coding efficiency than CAVLC. Therefore, for high quality video application, this paper proposes new binarization methods about the quantized DCT coefficients that are partitioned into four regions such that CABAC shows similar coding efficiency to CAVLC at high bitrate. The proposed binarization methods consist of separate binarization tables about the four partitioned DCT coefficients considering the statistical characteristics of the quantized DCT coefficients. The proposed binarizaton method for the quantized DCT coefficients shows higher coding efficiency than CABAC in H.264/AVC and shows very similar result to CAVLC at high bitrate.

• Journal of Chest Surgery
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• v.25 no.5
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• pp.469-479
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• 1992

Searching for the clinical effects of colloid solutions that used to increasing the oncotic pressure of priming solutions at the cardiopulmonary bypass, 29 patients [who were diagnosised as simple VSD around 10kg of body weight and scheduled to be operated from June 1990 to December 1990 at Sejong General Hospital] were divided randomly and prospectively to the two groups: A group [15] was received 4gm% albumin as addition to the priming solutions and B Group [14] the same amount of Ringer`s lactated solution. 34 clinical parameters [Body weight, sex, age, body surface area, Qp/Qs, pulmonary arterial pressure, cardiopulmonary bypass time, anesthetic time, intraoperatively infused crystalloid and colloid amount, hemoglobin, hematocrit, serum sodium concentration, serum osmolarity, urine osmolarity, urine specific gravity, serum concentration, serum osmolarity, urine osmolarity, urine specific gravity, serum protein, serum albumin concentration, urine output, central venous pressure, postoperatively infused colloid amount, immedediate post-operative peak inspiratory pressure, cardiac index, blood pressure and pump flow during cardiopulmonary bypass, inotro-pic assist, diuretics, extubation period, total drain amount, duration of ICU] were measured and compaired between the two groups. There were no differences of preoperative and operative clinical parameters. And postoper-atively, practically there were no nearly differences at the clinical outcomes between the two groups, but some parameters [cardiac index, PIP, BP and pumpflow during CPB, etc] contributed to being preferable to the Group A at certain times [P<0.05]. Conclusively, it might be thought that the priming solution of cardiopulmonary bypass added by colloid solution had some beneficial effects on the patients, especially younger and associated with complex anomaly to be expected taken longer time of cardiopulmonary bypass, and more studies about the neonatal and complex anomaly cases were needed in that points.