• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.127-132
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• 2006

Quantization in video coding plays an important role in controlling the bit-rate of compressed video bit-streams. It has been used as an important control means to adjust the amount of bit-streams to at]owed bandwidth of delivery networks and storage. Due to the dependent nature of video coding, dependent quantization has been proposed and applied for MPEG-2 video coding to better maintain the quality of reconstructed frame for given constraints of target bit-rate. Since Scalable Video Coding (SVC) being currently standardized exhibits highly dependent coding nature not only between frames but also lower and higher scalability layers where the dependent quantization can be effectively applied, in this paper, we propose a dependent quantization scheme for SVC and compare its performance in visual qualities and bit-rates with the current JSVM reference software for SVC. The proposed technique exploits the frame dependences within each GOP of SVC scalability layers to formulate dependent quantization. We utilize Lagrange optimization, which is widely accepted in R-D (rate-distortion) based optimization, and construct trellis graph to find the optimal cost path in the trellis by minimizing the R-D cost. The optimal cost path in the trellis graph is the optimal set of quantization parameters (QP) for frames within a GOP. In order to reduce the complexity, we employ pruning procedure using monotonicity property in the trellis optimization and cut the frame dependency into one GOP to decrease dependency depth. The optimal Lagrange multiplier that is used for SVC is equal to H.264/AVC which is also used in the mode prediction of the JSVM reference software. The experimental result shows that the dependent quantization outperforms the current JSVM reference software encoder which actually takes a linear increasing QP in temporal scalability layers. The superiority of the dependent quantization is achieved up to 1.25 dB increment in PSNR values and 20% bits saving for the enhancement layer of SVC.

• Journal of Chest Surgery
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• v.17 no.4
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• pp.607-613
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• 1984

Thirty seven patients with ostium secundum atrial septal defect, operated from January, 1976 to September, 1984 at the Department of Thoracic and Cardiovascular Surgery, Kyungpook National University Hospital, were given clinical assessment. The following results were obtained. 1.Ostium secundum atrial septal defect was comprised of 18% of congenital heart disease. Their mean age was 15.7\ulcorner.42. Sex ratio [male:female] was 1:1.1. 2.Most frequent clinical symptom was dyspnea on exertion occurred in 26 patients [76.5%]. Only one patient had no symptom [2.9%]. 3.Pre-operative EKG findings revealed RVH in 61.8%, ICRBBB in 29.4%, and RAD in 41.2%. 4.Mean value of systolic pulmonary arterial pressure in patients over 20 years old was 37.8\ulcorner4.4mmHg and it was 28.1\ulcorner10.2mmHg in patients under 20 years old, but the difference between two groups was not statistically significant. 5. In large defect group [>3cm in diameter], Qp/Qs was significantly increased than small defect group [<3cm in diameter], but systolic pulmonary arterial pressure and Rp/Rs were not different between two groups. 6. Overall operative mortality was 5.4%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.1
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• pp.53-63
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• 1997

In this paper, we present a new macroblock-based bit allocation scheme in multiple MPEG-1 video encoders system and a single multiplexer over a single channel. The proposed scheme models the relations between fate(Bits/MB) and distortion(MSE/MB), rate and quantizer parameter(QP), distortion and quantizer parameter, respectively, in the same form. By using these relations, we minimize the Larangian cost function to obtain a bit allocation scheme based on macroblock unit. Experimental results show that the proposed scheme can reduce MSE compared to other conventional buffer-based rate control methods, i.e. independent buffer control method and shared common buffer control one. And we confirmed, through computer simulation, that the proposed scheme can be effectively modified to maintain the objective quality of a specific video service at a constant level.

• Journal of Chest Surgery
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• v.21 no.1
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• pp.143-147
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• 1988

Congenital coronary arteriovenous fistula is a communication of a coronary artery with one of the atria, ventricles, the coronary sinus, the superior vena cava, or the pulmonary artery. We had a successful surgical experience with 63 year-old-female patient who complained substernal chest pain on exertion for 8 years. On auscultation, a continuous murmur was heard at the left second to third intercostal space along the left sternal border. The right cardiac catheterization was revealed to 4% oxygen step up between right ventricle to main pulmonary artery, and Qp/Qs was 1.3:1. The selective coronary arteriography showed markedly tortuous dilated vessel which originated from left coronary artery draining into the main pulmonary artery. The operation performed to mid portion of tortuous and dilated fistula by multiple ligation with 3-0 Mersilene and suture ligation with pledgetted 3-0 Prolene on distal draining site, Postoperative course were uneventful without any symptoms and complications.

• Journal of Chest Surgery
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• v.17 no.4
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• pp.636-643
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• 1984

For the purpose of avoiding postoperative massive pulmonary insufficiency after transannular outflow tract reconstruction in patients with tetralogy of Fallot, we have used monocusp bearing outflow patch since June 1983. Right heart catheterization and pulmonary arteriography were performed in 7 patients among the total 11 patients corrected with monocusp bearing outflow patch during postoperative 14th day to 22nd day. Particular attention was paid to the evaluation of the pulmonary valve competence, and the results were; 1.One patient died of acute renal failure secondary to low cardiac output and the operative mortality was 9.1%. 2.The average PRV/FA ratio was 0.491 and the average systolic pressure gradient between right ventricle and pulmonary artery was 17.7mmHg. The average Qp/Qs was 1.13. 3.Inspite of using monocusp bearing outflow patch, the hemodynamic and pulmonary arteriographic results were unsatisfactory in respect to pulmonary valve competence.

• Journal of Chest Surgery
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• v.21 no.3
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• pp.588-593
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• 1988

We experienced a case of interrupted aortic arch[Type A] associated with PDA, VSD, mitral regurgitation and single coronary artery. The patient was 7 years old boy, who showed congestive heart failure[NYHA functional class III]. One stage total correction was performed under profound hypothermia with total circulatory arrest. Aortic continuity was established using PDA with anterior wall of main pulmonary artery flap. VSD was closed with Dacron patch and mitral regurgitation repaired by Reed`s annuloplasty method. The postoperative cardiac catheterization revealed no pressure gradient between ascending aorta and descending aorta, decreased pulmonary artery pressure and trivial residual shunt[Qp/Qs: 1.28]. The aortogram showed good continuity of the aorta without narrowing of the anastomotic site. During the period of 1 year follow up, heart failure symptoms were nearly subsided.

• Journal of Chest Surgery
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• v.16 no.4
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• pp.511-517
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• 1983

For the purpose of clinical analysis of secundum atrial septal defect, the patients with atrial septal defect operated on during the period from Aug. 1959 to Aug. 1983 were analysed. The age of the patients was ranged from 3 months to 60 years and there were 132 males [45.3%] patients and 145 female patients [54.6%] in this series. The most frequent type was oval type defect in 219 [86.9%]. The PAPVC were present in 7 patients of high defect group. Clinical analysis revealed 53 patients [19.9%] were asymptomatic. The QP/QS above than 3.61 were 45 patients and less than 1.5 were 24 patients. The pulmonary artery pressure was 10 to 100 mmHg. The majority of the defects were closed in primary suture and closed with a Dacron patch in 19 patients. The postoperative complications occurred in 35 patients [13.1%] and the most frequent complication was wound problem which was present in 10 patients. The hospital mortality rate was 1.6%.

• Journal of applied mathematics & informatics
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• v.27 no.3_4
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• pp.567-579
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• 2009

Recently, Peng et al. proposed a primal-dual interior-point method with new search direction and self-regular proximity for LP. This new large-update method has the currently best theoretical performance with polynomial complexity of O($n^{\frac{q+1}{2q}}\;{\log}\;{\frac{n}{\varepsilon}}$). In this paper we use this search direction to propose a primal-dual interior-point method for convex quadratic programming (QP). We overcome the difficulty in analyzing the complexity of the primal-dual interior-point methods for convex quadratic programming, and obtain the same polynomial complexity of O($n^{\frac{q+1}{2q}}\;{\log}\;{\frac{n}{\varepsilon}}$) for convex quadratic programming.

• Journal of the Optical Society of Korea
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• v.4 no.1
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• pp.19-22
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• 2000

A new image encoding and identification scheme is proposed for security verification by us-ing a CGH(computer generated hologram), random phase mask, and a correlation technique. The encrypted image, which is attached to the security product, is made by multiplying a QP- CGH(quadratic phase CGI) with a random phase function. The random phase function plays a key role when the encrypted image is decrypted. The encrypted image can be optically recovered by a 2-f imaging system and automatically verified for personal identification by a 4-f correlation system. Simulation results show the proposed method can be used for both the reconstruction of an original image and the recognition of an encrypted image.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.10
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• pp.10-18
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• 1992

This paper considers and implementation of the memory system which provides simultaneous access to pq image points of block(p$\times$q), horizontal vector(1$\times$pq)and/vertical vector(pq$\times$1) in 2-dimension image array, where p and q are design parameters. This memory system consists of an address calculation circuit, address routing circuit, data routing circuit, module selection circuit and m memory modules where m>qp. The address calculation circuit computes pq addresses in parallel by using the difference of addresses among image points. Extra module assignment circuit is not used by improving module selection circuit with routhing circuit. By using Verilog-XL logic simulator, we verify the correctness of the memory system and estimate the performance. The implemented system provides simultaneous access to 16 image points and is 6 times faster than conventional memory system.