• Journal of Korea Multimedia Society
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• v.15 no.11
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• pp.1330-1340
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• 2012

In this paper, a new algorithm is proposed for the heart valves stenosis region detection using heart sounds. Many researches for detecting primary components or removing heart murmurs have been studied, but their performances are degraded at abnormal heart sounds such as aortic stenosis and mitral stenosis because of large heart murmurs. In this paper, heart murmur detection method is proposed based on noise intensity function. The proposed noise intensity function detect the primary components S1, S2, then set session up using S1, S2. And then noise intensity function was computed using autocorrelation value of each session. The proposed noise intensity function estimated noise intensity of each sessions and detected heart murmurs. According to simulation results, the proposed algorithm has better performance than former study for detecting heart valve stenosis region.

• Journal of Veterinary Clinics
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• v.25 no.3
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• pp.195-199
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• 2008

A 2-year-old female Maltese dog was referred with primary complaints of exercise intolerance and abnormal heart sound. Clinical and diagnostic investigation revealed split S2 and S4 gallop in the cardiac auscultation, tall P wave and left anterior fascicular block in the electrocardiogram, left atrial enlargement on the thoracic radiography, ostium primum atrial septal defect and cleft of the anterior leaflet of the mitral valve on the echocardiography. Based on those findings, the dog was diagnosed as the partial atrioventricular canal defect. Since the dog showed mild exercise intolerance, enalapril and furosemide were prescribed.

• Journal of Chest Surgery
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• v.15 no.2
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• pp.238-242
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• 1982

The incidence of annuloaortic ectasia has known rare, and approximately 5-10% of aortic regurgitation. The patient was 44 years old male who complained exertional dyspnea and left anterior chest pain. He had done Lt. side 2 stage thoracoplasty for pulmonary tuberculosis about 20 years ago at Dept.of Chest surgery of National Medical Center. At that time, there was no abnormal findings in cardiovascular system. The preoperative aortic cineangiogram showed pear shaped dilatation [7.3 cm x 6.8 cm] of aortic mot with aortic valve regurgitation but left ventricular ejection function was fair. Preop. ventilatory function test showed mixed type pulmonary insufficiency. Recently, we corrected surgically, by AVR with Carpentier-Edwards Bioprosthesis [29mm] & supracoronary Woven Dacron graft [29mm x 5cm] replacement, with good clinical result for follow up 6 months.

• Journal of Chest Surgery
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• v.19 no.2
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• pp.313-318
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• 1986

A rare anomaly, Cor triatriatum dexter combined with pulmonary stenosis and patent foramen ovale in a 2-years- old female is presented. Abnormal embryologic development of the right sinus venosus valve caused partial membranous septation of the right atrium. Most cases have been recorded at necropsy either as an incidental finding or in association with severe congenital heart disease. In this case, Cor triatriatum dexter was diagnosed preoperatively by cineangiography and echocardiography.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.12 no.2
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• pp.25-33
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• 2016

The thermal stratification phenomenon in the nuclear power plant can cause abnormal deformation of the piping, contact with the support, damage to the support system. Repetition of the thermal stratification phenomenon or variation of the thermal boundary layer can cause thermal fatigue. Thermal stratification phenomenon in nuclear power plants is still an ongoing issue and active research has been carried out. In this paper, the current situation in Korean nuclear power plants is described, followed by the status of research and the future problems on the thermal stratification phenomenon in Korea.

• Journal of Chest Surgery
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• v.14 no.1
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• pp.49-59
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• 1981

This is one case report of surgically treated partial atrioventricular canal. The 22 year-old male patient had no definitive history of frequent respiratory infection and cyanosis in his early childhood. Since his age of 7 years, dyspnea was manifested on exertion. First appearance of congestive heart failure was at his age of 16 years old. The physical examination revealed that the neck veins were distended and heaving of precordium. A thrill was palpable on the left 3rd-4th intercostal space extending from the sternal border toward the apex and Grade IV/VI systolic ejection murmur was audible on it. Neither cyanosis nor clubbing was noted. Liver was palpable about 5 finger breadths. Chest X-ray revealed increased pulmonary vascularity and severe cardiomegaly (C-T ratio = 74%). EKG revealed LAD, clockwise rotation, LVH and trifascicular block. Echocardiogram showed paradoxical ventricular septal movement, narrowed left ventricular outflow tract and abnormal diastolic movement of the anterior leaflet of mitral valve. Right heart catheterization resulted in large left to right shunt (Qp : Qs = 5.7: 1), ASD and moderate pulfllonary hypertension. Finally, left ventriculogram revealed typical goose neck appearance of left ventrlcalar outflow tract. On Oct. 10, 1980, open heart surgery was performed. Operative findings were: 1. Large primum defect ($6{\times}5$ Cm in diameter) 2. Cleft on the anterior leaflet of mitral valve. 3. The upper portion of ventricular septum was descent but no interventricular communication. 4. Downward attachment of the atrioventricular valves on the ventricular muscular septum. 5. Medium sized secumdum defect ($2{\times}1$ Cm in diameter). The cleft was repaired with 4 interrupted sutures. The primum defect was closed with Teflon patch and the secundum defect was closed with direct suture closure. Postoperatively atrial flutter-fibrillation in EKG and Grade U/VI apical systolic murmur were found. The postoperative course was uneventful and discharged on 29th postoperative day in good general conditions.

• Journal of Chest Surgery
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• v.36 no.7
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• pp.523-526
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• 2003

A 44-year-old man had been admitted for dyspnea on exertion and abdominal distension. The echocardiography revealed abnormal mass in right atrium and tricuspid valve stenosis with right ventricular obliteration. The operation was performed with mass removal, enlargement of tricuspid valve opening, and right ventricular endocardiectormy. And then, atrial septal defect was made due to inadequate right ventricular volume. The patient's symptom was improved and he discharged without events. The endomyocardial fibrosis was diagnosed with microscopic examination. Eighteen months later, the patient was readmitted due to aggravated dyspnea and cyanosis. The right ventricular obliteration was progressed and pulmonary blood flow was severely decreased in follow up echocardiography. Palliative bidirectional cave-pulmonary shunt was performed due to functional single ventricle. The dyspnea and cyanosis was markedly improved. Bidirectional cavo-pulmonary shunt for advanced and isolated right ventricular endomyocardial fibrosis provided effective palliation at early postoperative period, However, long-term follow up is mandatory.

• Journal of the Korean Institute of Gas
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• v.23 no.6
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• pp.1-7
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• 2019

Most oil refineries and chemical plants have flare systems designed to mitigate pressure rises in process facilities in case of emergencies that require the release of large amounts of gas due to sudden process shutdowns such as power outages. However, the rise of the flame of the flare system causes civil complaints from residents around the factory due to visible pollution, and economic loss occurs in the company, which requires constant management. In this study, two items were diagnosed and analyzed in order to derive the optimal operation method of flare system. First, to detect the cause of the rise in flame height, the acoustic leak detector was used to check gas leaks in safety valves and pressure control valves. Second, to identify the cause of flame instability, the pulsation phenomenon was diagnosed through the CFD simulation and modeling experiments of the sealing drum. By confirming the leak at 4.3% of the safety valve and 10% of the pressure control valve, the cause of abnormal sparking was derived. The information presented in this study can be easily applied to any company that has a flare system, and is expected to prevent complaints and product loss.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.464-469
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• 2019

A remote monitoring panel and control system was developed to control various valves and access control chambers, including gas shutoff valves used in CBR(Chemical, Biological and Radiological) facilities. The remote monitoring panel consisted of a main panel installed in the NBC (Nuclear, Biological and Chemical) control room and auxiliary panel installed in the clean room, and the size was divided into pure control and control including CCTV. This system can be monitored and controlled remotely according to the situation where an explosion door and gas barrier door can occur during war and during normal times. This system is divided into normal mode and war mode. In particular, it periodically senses the operation status of various valves, sensors, and filters in the CBR facilities to determine if each apparatus and equipment is in normal operation, and remotely alerts situation workers when repair or replacement is necessary. Damage due to the abnormal operation of each device in the situation can be prevented. This enables control of the blower, supply and exhaust damper, emergency generator, and coolant pump according to the state of shutoff valve and positive pressure valve in the occurrence of NBC, and prevents damage caused by abrupt inflow of conventional weapons and nuclear explosions.

• Journal of Korea Water Resources Association
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• v.55 no.spc1
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• pp.1211-1222
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• 2022

Abnormal condition inevitably occurs during operation of water distribution system (WDS) and requires the isolation of certain areas using isolation valves. In general, the determination of the optimal location of isolation valves considered minimization of hydraulic failures as isolation of certain areas causes a change in hydraulic states (e.g., flow direction, velocity, pressure, etc.). Water quality failure can also be induced by changes in hydraulics, which have not been considered for isolation valve system design. Therefore, this study proposes a new isolation valve system design methodology to prevent unexpected water quality failure events. The new methodology considers flow direction change ratio (FDCR), which accounts for flow direction changes after isolation of the area, as a constraint while reliability is used as the objective function. The optimal design model has been applied to a synthetic grid network and the results are compared with the traditional design approach. Results show that considering FDCR can eliminate flow direction changes while average pressure and coefficient of variation of pressure, velocity, and hydraulic geodesic index (HGI) outperform compared to the traditional design approach. The proposed methodology is expected to be a useful approach to minimizing unexpected consequences by traditional design approaches.