• Journal of computational fluids engineering
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• v.13 no.3
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• pp.51-61
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• 2008

The SMAC (Simplified Marker And Cell) algorithm is extended for an application to thermal non-equilibrium two-phase flows in light water nuclear reactors (LWRs). A two-fluid three-field model is adopted and a multi-dimensional unstructured grid is used for complicated geometries. The phase change and the time derivative terms appearing in the continuity equations are implemented implicitly in a pressure correction equation. The energy equations are decoupled from the momentum equations for faster convergence. The verification of the present numerical method was carried out against a set of test problems which includes the single and the two-phase flows. The results are also compared to those of the semi-implicit ICE method, where the energy equations are coupled with the momentum equation for pressure correction.

• Journal of Chest Surgery
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• v.20 no.4
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• pp.780-785
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• 1987

Pulmonary atresia with VSD is uncommon congenital anomaly with high mortality in neonatal period. Recently we experienced surgical correction of 2 cases of pulmonary atresia with VSD. The first case was 7-year old female patient and diagnosed as pulmonary atresia with VSD combined PDA. So, total correction was undertaken which consisted of PDA ligation, patch repair of VSD, transannular enlargement of RVOT with woven Dacron vascular graft, and closure of PFO. Postoperative systemic Rt. ventricular and radial artery pressure ratio was 0.44 and her postoperative course was uneventful. The second case was 6-year old male patient diagnosed as pulmonary atresia with VSD and large systemic-pulmonary collateral arteries. There were two large systemic-pulmonary collaterals, one was simply controlled by ligation, but the other was considered to supply Rt. upper lung. So end to side anastomosis was performed to the RVOT patch. Postoperative systolic Rt. ventricular and radial artery pressure ratio was 0.54. During the follow up period he showed clinical picture of Rt. heart failure, which is relatively well controlled with anticongestive therapy.

• Journal of Chest Surgery
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• v.10 no.1
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• pp.90-97
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• 1977

This is a report of a. case in which a long narrow segment coarctation of the aorta was successfully corrected with Teflon graft. The patient was 30 year old man with hypertensive symptoms that occurred 7 years prior to operation. Blood pressure measured 230/110 mmHg in the arms and 110/80 mmHg in the legs. Pulses were strongly tensive in radial artery, but very weak in femoral artery and even absent in dorsal pedis artery. Final preoperative diagnosis was made by aortography which showed a long narrow segment between aortic arch and descending thoracic aorta and highly developed collateral circulations. A long hypoplastic narrow segment was located proximal to the ligament arteriosus, and diaphragmatic stenosis of the aorta was located just distal to the ligamentum arteriosus. After prosthetic correction of the coarctation of the aorta, blood pressure were measured 130/ 80 mmHg in the arms and 150/100 mmHg in the legs. Peripheral pulses were palpated normally, and the postoperative course was uneventful.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.291-292
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• 2019

본 논문에서는 자세 교정에 도움을 줄 수 있는 압력센서 기반의 스마트 방석 개발 사례를 소개한다. 스마트 방석은 스마트폰과 블루투스로 연결되며 스마트폰 앱은 사용자의 자세 정보를 분석한 후 자세가 불안정한 징후가 판단되면 알림을 통해 바람직한 자세를 취할 수 있도록 안내한다. 본 시제품 개발에서는 압력센서의 값을 분석한 후 단순한 형태의 자세 추정 방식을 채택하였지만 향후 다양한 실험 및 딥러닝 응용을 통해 정확한 자세 추정을 위한 알고리즘을 개발할 계획이며 알림에 의한 수동적 자세 교정이 아닌 기구 설계, 모터 제어 등을 통해 능동적인 자세 교정을 지원하는 스마트 방석을 개발할 계획이다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.8
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• pp.30-36
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• 2002

Wind tunnel model has some difference in shape compared to the real flight vehicle because of model support system for testing. The support system can make some differences in the measured forces and moments to the flight test data. There are several correction methods involved such as cavity pressure correction and model support interference. Internal balance and belly sting support were used for this wind tunnel test and three types of model support correction methods, variable sting thickness method, dummy sting method, and wire support method, were compared. Variable sting thickness method is well matched with wire support method, which is known for almost interference free.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.81-90
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• 2017

This paper presents a smart seat for correction of driver posture while driving. We introduce good postures with seat height, seat angle, head height, back of knees, distances of foot pedals, tilt of seat, etc. There have been some studies on correction of good posture while driving, effects of driving environment on driver's posture, sitting strategies based on seating pressure distribution, estimation of driver's standard postures, and others. However, there are a few studies on guide of good postures while driving for problem of driver's posture using machine leaning. Therefore, we suggest a smart seat for correction of driver's posture based on machine leaning, 1) developed the system to get postures by 10 piezoelectric effect element, 2) collect piezoelectric values from 37 drivers and 28 types of cars, 3) suggest 4 types of good postures while driving, 4) analyze test postures by kNN. As the results, we can guide good postures for bad or problems of postures while driving.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.7
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• pp.621-627
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• 2008

Aerodynamic data measured in a wind tunnel has inevitable errors due to the presence of the wind tunnel walls. These unwanted interference effects must be corrected for the wall interference free aerodynamic data. Streamline curvature effects are caused by straightening of streamlines due to wind tunnel walls. Classical Glauert's correction method that is a standard method for fixed wing aircraft is not suitable for rotary wing aircraft. In this paper, Heyson's correction method of which wake model is compatible with rotors is used to correct the rotor shaft angle as well as the dynamic pressure. The results of Heyson's method are compared with Glauert's correction method.

• Journal of Biomedical Engineering Research
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• v.28 no.2
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• pp.178-186
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• 2007

This study is attempted to correct an error of electronic blood pressure meter with an optical sensor. In general, for a hospitalized patient, ECG, blood pressure, oxygen saturation, and respiration are basically measured to monitor the patient's condition. Opening of a blood vessel after it is occluded by pressurizing the cuff influences the blood flow of peripheral blood vessels as well as oscillation changes in the cuff. Blood vessels are occluded and peripheral blood flow disappears at cuff pressure above the examinee's blood pressure, while blood vessels are opened and peripheral blood flow appears again at cuff pressure under the examinee's blood pressure. Then Disappear-Appear Point Length(DAPL) of peripheral blood flow can be judged with the signal of peripheral blood flow, thus is available as a factor of error correction for electronic blood pressure meter. Also, systolic or diastolic blood pressure can be corrected with Appear-Point-Pressure(APP) of cuff pressure at a point where blood flow occurs and Appear-Maximum Pressure(AMP) of cuff pressure at the maximum amplitude point of peripheral blood flow after peripheral blood flow appears again. For verification, 27 examinees were selected, and their blood value was obtained through experimental procedure of 4 stages including induction of blood pressure change. The examinees were divided into two groups of experimental group and control group, regression analysis was conducted for experimental group, and correction of a blood pressure error was verified with optical signal by applying the regression equation calculated in experimental group to control group. As an experimental result, mean of the whole measurement errors was 5mmHg or more, which did not meet the standard fur blood pressure meter. As a result of correcting blood pressure measurements with data of DAPL, APP, and AMP as drawn out of PPG signal, systolic blood pressure, mean blood pressure, and diastolic blood pressure were $-0.6{\pm}4.4mmHg,\;-1.0{\pm}3.9mmHg$ and $-1.3{\pm}5.4mmHg$, respectively, indicating that mean of the whole measurement errors was greatly improved, and standard deviation was decreased.

• Journal of Chest Surgery
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• v.22 no.2
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• pp.234-245
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• 1989

Between January 1984 and December 1986, sixty nine patients, aged 16 months to 25 years [mean age 10.05*6.40 years], underwent total correction of tetralogy of Fallot in Kyungpook national university hospital. In 66 hospital survivors, 30 patients were followed up for 12 to 48 months [mean 30.10*10.26 months]. These 30 patients were classified in two groups, TAP [transannular patch] and Non-TAP group. There were 9 patients in TAP group, and 21 in Non-TAP group. There were no significant differences between two groups in terms of age at operation, follow up duration, ACC time, and bypass time. All patients were evaluated by two dimensional echocardiography, Doppler echocardiography, standard 12-lead electrocardiography, and plain chest X-ray. Right ventricular systolic pressure, pulmonary arterial systolic pressure, pressure gradient between the right ventricle and the pulmonary artery, presence or absence of pulmonary regurgitation and its grading, fractional shortening of the left ventricle, and Qp/Qs in case of remnant ventricular septal defect were obtained by echocardiographic examination. Cardiothoracic ratio was measured by plain chest film, and ventricular dysrrhythmia was detected by electrocardiogram. Comparing the data between two groups, there was significant difference in incidence of postoperative pulmonary regurgitation [p< 0.05], 100%[9/9] in TAP group and 47.6 %[10/21] in Non-TAP group, but all the regurgitations were not severe. There were no significant differences in other comparisons, despite of higher incidence of cardiomegaly in TAP group [CT ratio: 59.3*5.3% VS 54.7*6, 4 %].

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.5
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• pp.535-544
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• 2009

Signals from the Global Positioning System(GPS) satellite are used to retrieve the integrated amount of water vapor or the precipitable water vapor(PWV) along the path between a transmitting satellite and ground-based receiver. In order to retrieve the PWV from GPS signal delay in the troposphere, the actual zenith wet delay, which can be derived by extracting the zenith total delay and subtracting the actual zenith hydrostatic delay computed using surface pressure observing, will be needed. Since it has been not co-located between GPS permanent station and automated weather station, the air-pressure on the mean sea level has been used to determine the actual zenith hydrostatic delay. The directly use of this air-pressure has been caused the dilution of precision on GPS PWV retrieval. In this study, Korean reverse sea level correction method of air-pressure was suggested for the improving of GPS PWV retrieval capability and the accuracy of water vapor estimated by GPS was evaluated through a comparison with radiosonde PWV.