• Journal of Chest Surgery
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• v.42 no.2
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• pp.193-200
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• 2009

Background: The long-term administration of oral anticoagulant to the patients with a mechanical heart valve prosthesis is mandatory. However, the appropriate intensity of oral anticoagulant therapy to prevent thromboembolic or hemorrhagic complications is still controversial. We tried to apply low intensity anticoagulant therapy for which the International Normalized Ratios ranged between 1.5 and 2.5, and we analyzed the anticoagulation-related long term outcomes. Material and Method: From January 1992 to December 2002, 144 patients who underwent a single cardiac valve replacement were included in the study, and their ages ranged from 15 to 72 years (mean age: $47.4{\pm}15.1$): there were 49 aortic valve replacements (AVR) and 95 mitral valve replacements (AVR). The patients were followed up monthly or bi-monthly at the outpatient clinic with clinical examinations and measuring the prothrombin time to adjust the International Normalized Ratios (INRs) within the low-intensity target range between 1.5 and 2.5. Result: The follow-up period was 835.3 patient-years (mean: $5.9{\pm}3.5$) and the INRs of 7,706 measurements were available for evaluation. The mean INRs of the aortic and the mitral valve replacement groups were significantly different (p<0.01). All the patients' INRs were within the target range in 61.9% of the measurements. The mean INRs $(2.16{\pm}0.23)$ of the patients with atrial fibrillation, which was found in 30.3% of the patients, were definitely higher than those $(2.03{\pm}0.27)$ measured in the patients with regular rhythm (p<0.01). Thromboembolic episodes occurred in 9 patients with an incidence of 1.08%/patient-year. Major bleeding occurred in 2 patients (MVR) with an incidence of 0.24%/patient-year. The patients who displayed better compliance showed a lower incidence of complications (p=0.000). Conclusion: The anticoagulation therapy with a low-intensity target range after MVR or AVR seems to be effective and feasible, and increasing the patients’ compliance should be done for achieving more effective anticoagulation therapy.

• Journal of Navigation and Port Research
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• v.32 no.1
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• pp.1-7
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• 2008

Since the shipbuilding industry is at its peak to assimilate the large volume of orders in recent years, the Floating Dock has been an alternative to the dry dock which takes a certain period of time to build. Hence the use of Floating Dock is steadily increasing. Since the Skid Launching System(SLS) is used in Floating Dock, the balancing of the ship while launching is important and achieved by adjusting the Ballast tank of the Floating Dock. In this paper a Floating Dock Control Simulator for SLS is developed through the on-line interface of VRC(Valve Remote Control), Tank Level & Draft Measuring System and Valve Control algorithm on Simulation Tank Plan.

• Fire Science and Engineering
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• v.29 no.3
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• pp.6-12
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• 2015

Indoor hydrant facilities are used to fight initial fires before more intense fire extinguishing activities. Fire extinguishing facilities should ensure good fire extinguishing performance and the safety of users. Indoor hydrant facilities are mostly installed in buildings and facilities, and users must manipulate valves, hoses, and nozzles manually. When the discharge pressure is higher than 0.70 MPa, there is a high possibility that problems with manipulation and hose breakdown can occur. To prevent these problems, a method to attach orifice-type decompression valves to the angle valves of indoor hydrant discharge outlets has frequently been used for decompression methods. However, the decompression performance was reduced due to structural problems of the decompression valves over time. Accordingly, based on three-stage initial pressures, applicable pressure ranges were selected by measuring the decompression performance according to the diameter of the decompression orifices. Based on the data, stable decompression valve models are proposed. These models have the lowest decrease in decompression performance, regardless of time.

• Journal of Navigation and Port Research
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• v.33 no.6
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• pp.375-380
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• 2009

The authors had consisted the construction of shipyard must be investigated under the consideration of long term ship's demand and so the Floating Dock might be an alternative to the dry dock. This paper shows a development of Floating Dock Controller for Skid Launching System(SLS). While loading out a block to the Floating Dock and launching ship from the Floating Dock, the balancing of the ship and the dock is very important and achieved by adjusting the Ballast tank of the Floating Dock In this paper a Floating Dock Controller for SLS was developed through the on-line interface of VRC(Valve Remote Control), Tank Level & Draft Measuring System and Valve Control algorithm on Tank Plan. The control system developed was applied to a shipbuilding and verified good and stable.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.5
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• pp.660-667
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• 2000

In order to investigate the exhaust structure and secondary oxidation of unburned hydrocarbon (HC) in the exhaust port, concentrations of individual HC species were measured in exhaust process, the degree of oxidation were obtained. Using a solenoid-driven fast sampling system on single-cylinder research engine fueled with 94% propane, the profiles of unburned hydrocarbons (HCs) and non-fuel HCs with a propane fueled engine were obtained from several locations in the exhaust port during the exhaust process. The sampled gases were analyzed using a gas chromatography of HC species with 4 or lesser carbon atoms. The change of total HC concentration and HC fractions of major components through the exhaust port were discussed. The results showed that non-uniform distribution of HC concentration existed around the exhaust valve and changed with time, and that the exhaust gas exhibited nearly uniform concentration profile at port exit, which was due to mixing and oxidation. Also it could be known that bulk gas with relatively high HC concentration came out through the bottom of the exhaust valve. To estimate the mass-based degree of HC oxidation in the exhaust port from measured HC concentrations, a 3-zone diagnostic cycle simulation and plug flow modeling were used. The degree of oxidation ranged between 26 % and 36 % corresponding to the engine operation conditions.

• Journal of Veterinary Clinics
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• v.36 no.2
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• pp.102-105
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• 2019

Nitrotyrosine was found to be dependent on the severity of myxomatous mitral valve disease (MMVD). However, a correlation of serum nitrotyrosine concentration in dogs with MMVD and the progression of the disease has not been investigated. This study compared changes in serum nitrotyrosine concentration with the progression of MMVD. Nine client-owned dogs were recruited for the study. Dogs were classified by measuring the amount of regurgitation using echocardiography into mild, moderate, or severe MMVD groups. Serum nitrotyrosine concentration was measured by an enzyme-linked immunosorbent assay test. Serum nitrotyrosine concentration was significantly higher at 180 days than at 0 day (P < 0.05). However, serum nitrotyrosine concentration at 360 days was lower than that at 180 days (P < 0.05). Serum nitrotyrosine concentration at 540 days was lower than at 180 days (P < 0.05). There was no correlation between serum nitrotyrosine and left atrial to aortic root diameter ratio (LA/Ao ratio) (n = 33, $R^2=0.003$, P = 0.759). Also, there was no correlation between serum nitrotyrosine and vertebral heart score (VHS) (n = 33, $R^2=0.026$, P = 0.368) and left ventricular end-diastolic diameter, normalized for body weight by the formula (LVEDDN) (n = 33, $R^2=0.053$, P = 0.196). The results of the study suggest that the progression of MMVD is correlated with changes in serum nitrotyrosine concentration, which shows potential for use as a cardiac biomarker which can be used to analyze the progression of disease in MMVD.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.778-784
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• 2017

We investigated the possibility of a bio-monitoring system for predicting toxic dinoflagellates (Genus Alexandrium) by the measuring shell valve movements(SVMs) of Pacific oyster, Crassostrea gigas (Mollusca: Bivalvia) using the Hall element sensor. We then described the SVMs of Pacific oyster exposed to the toxic algae under laboratory conditions. Pacific oyster used for experiment were fed Isochrysis galbana until they stabilized and kept under hunger conditions for three days to prevent the influence of food before the experiment. Pacific oyster were exposed to the toxic dinoflagellate, A. fundyense, and the potentially toxic dinoflagellate, A. affine. When Pacific oyster were exposed to A. fundyense, SVMs increased over 10 times/hr at low cell densities of 20 cells/mL. SVMs increased again at $14.1{\pm}5.7times/hr$ at 500 cells/mL, and $27.9{\pm}11.1times/hr$ at the high cell density of 5,000 cells/mL. However, in the presence of A. affine, SVMs increased at $6.7{\pm}3.9times/hr$ until 300 cells/mL, while they increased greatly to $15.3{\pm}10.8times/hr$ at 1,000 cells/mL. The SVMs of Pacific oyster indicated differences depending on species for toxic dinoflagellates. Therefore, the SVMs of Pacific oyster could be useful for A. fundyense, but would bedifficult to apply for A. affine.

• Journal of the Korean Magnetics Society
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• v.23 no.6
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• pp.193-199
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• 2013

The regional distribution of magnetic isotropy depending on the post annealing condition for the dual-type structure GMR-SV (giant magnetoresistance-spin valve) of NiFe/Cu/NiFe/IrMn/NiFe/Cu/NiFe multilayer was investigated. The rotation of in-plane ferromagnetic layer induced by controlment of the post annealing temperature inside of the vacuum chamber. The magnetoresistive curves of a dual-type IrMn based GMR-SV depending on the direction of the magnetization easy axis of the free layer and the pinned layer are measured by between $0^{\circ}$ and $360^{\circ}$ angles for the applied fields. The optimum annealing temperature having a steady and isotropy magnetic sensitivity of 1.52 %/Oe was $107^{\circ}C$ in the rotational section of $0{\sim}90^{\circ}$. By investigating the switching process of magnetization for an arbitrary measuring direction, the in-plane orthogonal magnetization for the dual-type GMR-SV multilayer can be used by a high sensitive biosensor for detection of magnetized micro-beads.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.9
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• pp.607-616
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• 2019

Free body diagram analysis is done for key parts of pilot stage of LLV (Load Limit Valve) which is used to protect overload for static structural test of aerospace flight vehicle. It is shown through the analysis that diameter ratio($D_2)^{ten}/D_2)^{comp}$) of two poppets in a pilot stage must be equal to piston area ratio($A_{comp}/A_{ten}$) of a hydraulic actuator for making a poppet open consistently at constant force applied by an actuator. The result of the analysis is verified by measuring geometries of the poppets in the four different LLVs which are corresponding to four actuators with different capacity and have been used after being imported in this laboratory. Results of "Adjuster resolution tests" with two different pilot stages show the max. deviation of Fi(actuator force in instant of opening poppet) from average Fi obtained for each turn of adjuster is 0.3KN and max. deviation of the Fi normalized by average Fi of each turn of adjuster is 3.7%. From the results, it is verified that the two pilot stages with same poppet diameter ratio make a poppet consistently open at Fis within ${\pm}3.7%$ deviation from the average Fi. The deviation is shown to be caused from frictional force of O-ring in the poppet. Additionally, design factors for poppet spring and adjuster, which are also key parts of the pilot stage, are distinguished and procedure for deciding the factors are also shown in this study.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.143-148
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• 2003

This study was experimentally performed in order to estimate the errors due to the leakage of transmitter gaugelines in the orifice flow meter for natural gas. It would be a serious problem in safety if a large quantity of leak was occurred at the tubes or fittings like valve. But in most cases the safety problems might be rarely happened because the gas leak detectors could be operated in advance and the various kinds of inspection would be also fulfilled periodically. If the leakage was occurred continuously with an undetectable amount at the gaugelines for measuring the pressure or the differential pressure(DP), the amount of leakage might be an error or an unaccounted flow(UAE). In addition if the measuring value of pressure or DP were affected by the leakage, it might also be a measurement error. The experiments were performed to estimate the amount of leakage and to check the DP changes if it exited. First, through the measurement of the air pressure changes in the airtight container connected to a transmitter with gaugelines as the time passed, the amount of leakage causing from the fittings of gaugelines was roughly estimated. As changing the leak position of the gaugeline, the leak was intentionally made to break out. The variance of DP was checked as controlling the extent of leakage and compared to no leak conditions. Consequently, under the normal maintenance conditions, the result represented that the amount of leakage causing from the gaugelines was insignificant and also the DP changes on leakage conditions were too small to cause the errors of measurements.