• Journal of Chest Surgery
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• v.25 no.9
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• pp.976-981
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• 1992

The results of the clinical observations on the 158 cases of the mitral valvular heart disease treated at the Department of Thoracic and Cardiovascular Surgery, Masan Koryo General Hospital from June, 1986 to December, 1991 were as follows; 1. There were 50 men and 108 women with sex ratio 1: 2.2. 2. The age of patient varied widely from 13 years to 65years. 3. The preoperative functional level accoridng to the NYHA classification were class II, III, IV in 18%, 67%, 15%. 4. All 158 patients were operated on under direct vision using extracorporeal circulation, mitral valve replacement in 118 cases, mitral and aortic valve replacement 40 cases. 5. The follow up period was between 2 months and 65 months postoperatively. [mean 30.1 months] 6. The early operative motality was 5.7%[9 cases], late motality was 4%[6 cases]. 7. The cardiothoracic ratio in the chest X-ray decreased at the 6th month postoperation. [pre-op: 0.60$\pm$0.07, post-op: 0.56$\pm$0.06 p<0.01]

• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.645-654
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• 1989

The historical background of fish fermentation in Asia and other regions of the world is reviewed. The classification of fermented fish products in different regions is attempted with respect to the technology involved. The fermented fish products are largely divided into three groups; (1) high-salt, (2) low-salt, and (3) non-salt fermented. High-salt fermented products contain over 20％ of salt and are represented by fish sauce, cured fish and fish paste. Low-salt fermented products contain 6-18％ salt and are subdivided into lactic fermented products with added carbohydrate and acid pickling associated with low temperature. Non-salt fermented products are represented by the solid state bonito fermentation and some alkaline fermentation of flat fishes. The local names of the products in different regions are compared and classified accordingly. The microbial and biochemical changes during fish fermentation are considered in relation to the quality of the products, and their wholesomeness is reviewed.

• Journal of Chest Surgery
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• v.20 no.2
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• pp.367-373
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• 1987

Dissecting aneurysm has long been recognized as an ominous and highly lethal form of aortic disease. Aortic dissection are characterized by longitudinal separation of aortic media and extension proximally, distally or both from the site of intimal tear. DeBakey and associates defined three types based on where the process originates and how far extends. In type I, intimal tear is located in the ascending aorta and extend beyond the descending aorta. We experienced a case of dissecting aneurysm, Type I of DeBakey`s classification which dissection extend to the left iliac artery. The patient was 61 years old woman and suffered from excruciating pain on admission. Excision of aneurysm and ascending aorta reconstruction using to Dacron Vascular Prosthesis were performed under extracorporeal circulation. The post-operative course was uneventful and follow up is continued.

• Speech Sciences
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• v.7 no.1
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• pp.217-232
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• 2000

In this study, I investigate the role of post-consonantal fundamental frequency (F0) as a cue for automatic distinction of types of Korean stops and affricates. Rather than examining data obtained by restricting contexts to a minimum to prevent the interference of irrelevant factors, a relatively natural speaker independent speech corpus is analysed. Automatic and statistical approaches are adopted to annotate data, to minimise speaker variability, and to evaluate the results. In spite of possible loss of information during those automatic analyses, statistics obtained suggest that vowel F0 is a useful cue for distinguishing manners of articulation of Korean non-continuant obstruents having the same place of articulation, especially of lax and aspirated stops and affricates. On the basis of the statistics, automatic classification is attempted over the relevant consonants in a specific context where the micro-prosodic effects appear to be maximised. The results confirm the usefulness of this effect in application for Korean phone recognition.

• Journal of The Korean Astronomical Society
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• v.47 no.6
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• pp.219-233
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• 2014

The main site of dust formation is believed to be the cool envelopes around AGB stars. Nearly all AGB stars can be identified as long-period variables (LPVs) with large amplitude pulsation. Shock waves produce by the strong pulsation and radiation pressure on newly formed dust grains drive dusty stellar winds with high mass-loss rates. IR observations of AGB stars identify various dust species in different physical conditions. Radio observations of gas phase materials are helpful to understand the overall properties of the stellar winds. In this paper, we review (i) classification of AGB stars; (ii) IR two-color diagrams of AGB stars; (iii) pulsation of AGB stars; (iv) dust around AGB stars including dusty stellar winds; (v) dust envelopes around AGB stars; (vi) mass-loss and evolution of AGB stars; and (vii) contribution of AGB dust to galactic environments. We discuss various observational evidences and their theoretical interpretations.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.7
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• pp.819-825
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• 1988

An 1-bit DPCM image coding method is presented. Our method is specially designed to reduce the slope overload which seems to be the major performance degradation factor in 1-bit DPCM. In the present algorithm, based on the classification of neighborhoods by its flatness, slope strength and direction, predictor and quantizer operate adaptively through switching action. Compared with some other methods by computer simulation, proposed method shows improved performance in image quality as well as in signal to noise ratio. This gain mainly comes from the reduced slope overload and seems large to compensate the increased complexity in prediction. As a post processing, Lee filter is used to reduce the granular noise subjectively annoying in flat region.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.7
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• pp.98-105
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• 2000

In this study, we developed rotating machine vibration condition monitoring system based upon Windows NT and DSP Board. Developed system includes signal analysis module, trend monitoring and simple diagnosis using threshold value. Trend analysis and report generation are offered with database management tool which was developed in MS-ACCESS environment. Post-processor, based upon Matlab, is developed for vibration signal analysis and fault detection using statistical pattern recognition scheme based upon Bayes discrimination rule and neural networks. Concerning to Bayes discrimination rule, the developed system contains the linear discrimination rule with common covariance matrices and the quadratic discrimination rule under different covariance matrices. Also the system contains k-nearest neighbor method to directly estimate a posterior probability of each class. The result of case studies with the data acquired from Pyung-tak LNG pump and experimental setup show that the system developed in this research is very effective and useful.

• Journal of Chest Surgery
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• v.21 no.1
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• pp.158-163
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• 1988

12 Patients with thoracic aortic aneurysm were operated between May 1985 to Sept. 1987 at the our department, Hanyang University Hospital. We retrospectively evaluated the surgical results and considered diagnosis, surgical approach and perioperative problems of thoracic aortic aneurysm. There are 9 males and 3 females in the patients. The age ranged from 23 to 61 years with the mean age at 40.6 years. The cause of the aneurysm was atherosclerosis in 5, Marfan`s syndrome in 4, syphilis In 1, trauma in 1 and annuloaortic ectasia in 1 case. According to DeBakey`s classification, Type I was 1 case, Type II was 5 cases and Type III was 6 cases. Among 6 patients with ascending aortic aneurysm, Bentall`s operation in 4 cases and ascending aorta reconstruction using to Dacron Tube Graft in 2 cases were performed successfully. 6 cases with descending aortic aneurysm were managed by prosthetic graft replacement. Chylothorax was observed in 1 patient and postoperative hemorrhage necessitating reopening of the chest occurred in 4 of operative survivors. There were 2 hospital deaths; one patient was dead during the operation and one patient was dead during the post-operative course due to low cardiac output syndrome

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.667-672
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• 2007

Land-use in Cheongju region is changing rapidly because of the increased interactions of human activities with the environment as population increases. We used multi-temporal Landsat images (1991 and 2000) and DEM data in a post-classification analysis with GIS to map land-use distribution and to analyse factors influencing the land-use changes for Cheongju City. Land-use statistics revealed that substantial land-use changes have taken place and that the built-up areas have expanded by about $17.57km^2(11.47%)$ over the study period (1991-2000). Agricultural lands and forests have decreased substantially while urban and barren lands have been on the increase. Rapid economic developments together with the increasing population were noted to be the major factors influencing rapid land use changes. Urban expansion has replaced urban and barren lands, thereby affecting habitat quality and leading to serious environmental degradation.

• Selected Papers of The Society of Naval Architects of Korea
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• v.1 no.1
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• pp.91-100
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• 1993

A displacement-based finite element method Is presented for the geometrically nonlinear analysis of eccentrically stiffened plates. A nonlinear degenerated shell element and a nonlinear degenerated eccentric isoparametric beam (isobeam) element are formulated on the basis of Total Agrangian and Updated Lagrangian descriptions. In the formulation of the isobeam element, some additional local decrees of freedom are implementd to describe the stiffener's local plate buckling modes. Therefore this element can be effectively employed to model the eccentric stiffener with fewer D.O.F's than the case of a degenerated shell element. Some detailed buckling and nonlinear analyses of an eccentrically stiffened plate are performed to estimate the critical buckling loads and the post buckling behaviors including the local plate buckling of the stiffeners discretized with the degenerated shell elements and the isobeam elements. The critical buckling loads are found to be higher than the analytical plate buckling load but lower than Euler buckling load of the corresponding column, i.e, buckling strength requirements of the Classification Societies for the stiffened plates.