• Journal of the Society of Naval Architects of Korea
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• v.60 no.1
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• pp.10-19
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• 2023

Blast Hardened Bulkhead (BHB) is an important measure that can increase the ship's survivability as well as protect the lives of the crew by mitigating the damage extent caused by an internal explosion in the ship. In particular, both the pressure and the shock impulse should be considered when designing the BHB against reflected shock waves having a high pressure with a short duration. This study proposes a design method for BHB that considers both the pressure and the shock impulse generated during the internal explosion. In addition, analysis and design concepts for accident loads such as explosion, fire, and collision of NORSOK and DNVGL, one of the international design guidelines for the curtain plate type blast hardened bulkhead type applied by the Korean Navy, are utilized. If this method is applied, it is expected that it can be used as a design concept for the pressure as well as the shock impulse of the explosion load of the curtain plate.

• Journal of Agricultural Extension & Community Development
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• v.2 no.1
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• pp.1-21
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• 1995

This study examines the socioeconomic returns to agricultural research and extension services in Korea, using multivariate time series technique and Akino-Hyami formula. Results find that the socioeconomic returns are quite competitive in case of agricultural research with 44.82% internal rate of return and very high in case of extension services with 207.82% internal rate of return. Agricultural production responds to the agricultural research shock about four years after the shock. The magnitudes of the impacts increase until a peak is reached nine years after the initial expenditures and the impacts declines to a zero level after about twenty years. This lag lengths are consistent to the usual literature on research, which finds lags of seven to thirty years. Agricultural production responds to an agricultural extension shock immediately and declines to a zero level after about four years. Thus, the lag lengths are much shorter than those by research shock.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.2
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• pp.192-201
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• 2001

Analyzing internal structure, flow rate and dynamic behavior characteristics of electronically controlled shock absorber, damping performance limit is identified to comprise the two reciprocal characteristics of ride comfort and handling safety. Regardless of its lower performance than the active suspension control system, the semi-active suspension control system has been taking interest because of its absolutely higher performance than passive suspension system. Since the pervious studies have been concentrated mostly on analytic aspect and survey on the internal structure of the shock absorber remain insufficient, the main discourse of this paper is focused on analyzing the nonlinear shock absorber which varies the damping force of semi-active suspension system and the dynamic characteristics of the solenoid valve, a sort of pressure valve, and proposing the design factors of importance.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.3
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• pp.1-13
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• 2021

Effects of the nozzle wall angles on the supersonic flow field in a thrust optimized nozzle were numerically investigated. The combustor and operating condition of 30-tonf rocket engine was selected to study the optimum nozzle shape. The nozzle flow of combustion products was realized by the shifting equilibrium calculation for the propellant of kerosene-LOx. The change of nozzle wall angles induced different developing patterns of the internal and secondary shock wave. The optimum nozzle was obtained when the internal shock was in a specific position at the nozzle outlet. The nozzle wall angles of the optimum nozzle were very similar to those of the optimum nozzle which does not consider the shock wave.

• Tuberculosis and Respiratory Diseases
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• v.69 no.6
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• pp.480-482
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• 2010

Rectus sheath hematoma (RSH) is a rare condition caused by hemorrhage into the rectus sheath. It is usually associated with severe cough, abdominal surgery, coagulopathy, and anticoagulation treatment. RSH can be difficult to diagnose and can be misdiagnosed as acute appendicitis, as diverticulitis, or as an ovarian mass. Although RSH usually presents as a benign condition, it can be life threatening, especially in the critically-ill patient. Here, we report a case of fatal RSH due to hypovolemic shock in a critically-ill 73-year-old woman, who had received heparin treatment due to acute myocardial infarction in the intensive care unit and who had been successfully treated by conservative management.

• Korean Circulation Journal
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• v.48 no.12
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• pp.1163-1164
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• 2018

• Journal of Yeungnam Medical Science
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• v.17 no.1
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• pp.31-38
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• 2000

Background: We sought to examine the use and outcomes of early intraaortic balloon counterpulsation(IABP) combined with early reperfusion therapy in patients presenting cardiogenic shock complicated acute myocardial infarction. The usc of IABP in patients with cardiogenic shock is widely accepted. However there is not ample information on the use of this technique in patients with cardiogenic shock who arc treated with reperfusion therapy in Korea. Materials and Methods: Twenty-eight patients presented with cardiogenic shock were classified into two groups: the early IABP group (insertion within 12 hours after AMI onset time) and the late IABP group (insertion after 12 hours). We compared In-hospital mortality between the two groups (early IABP group vs late IABP group). Results: Two groups showed no significant difference in clinical feature and coronary angiographic results. Among total 28 patients, 7 patients were treated with thrombolytic therapy and 21 patients with PTCA. Insertion site bleeding, fever, thrombocytopenia were reported as some of the complications of IABP insertion. In-hospital mortalities in the early IABP group and late IABP group were 4 patients(25%) and 8 patients(66%), respectively(p<0.05). Early IABP insertion and early PTCA showed lower hospital mortality rates. There was significant difference in the time to PTCA after AMI onset between the two groups(p<0.05). Conclusion: IABP appears to be useful in patients presenting cardiogenic shock unresponsive medical therapy. Early IABP insertion and early reperfusion therapy may reduce in-hospital mortality rates of post-MI cardiogenic shock patients.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.4
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• pp.467-478
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• 2003

Automotive shock absorber may not be regarded as only one(simple) damping machine because it is composed of many components, and shows non-linear damping characteristics. No matter how advanced form of shock absorber is developed, the oil shock absorber can not be neglected. because their structures are based on the oil shock absorber. Therefore it is essential to accurately analyze the dynamic characteristics of oil shock absorber. It stands mainly roi damper valve tuning which nowadays is still exhaustively done by means of ride work. In this study, damping mechanism and dynamic characteristics for oil shock absorber of twin tube type are analyzed, based on the mathematical model considering internal flow and pressure. For the reliability of numerical prediction. the database is constructed within the limit of adequate reliability. Finally, the programmed system that gives out necessary specification by inputting damping specification and tolerance is to be constructed.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.2
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• pp.220-225
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• 2002

To determine the anti-stress effect of KCG(加味天麻鉤藤飮) extract on sprague-dawley rats. we conducted a research about the change of weight, activity, reactivity, c-fos protein, cytotoxicity against PC12 cell line and heal shock protein. 1) KCG extract siginificantly inhibited the decrease of body weight induced by stress, compared with the control group. 2) KCG extract had no siginificant effect in the activity and reactivity of rats between the control and the experimental groups. 3) KCG extract siginificantly restrained c-fos protein manifestation, compared with the control group. 4) KCG extract siginificantly restrained heat shock protein, compared with the control group. These results suggested that KCG might be usefully anti-stress effect.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.4
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• pp.933-945
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• 1994

A shock-wave in a supersonic flow can be theoretically determined by a given pressure ratio at upstream and downstream flowfields, and then the obtained shock-wave is stable in its position. Under the practical situation in which the shock-wave interacts with the boundary layer along a solid wall, it cannot, however, be stable even for the given pressure ratio being independent of time and oscillates around a time-mean position. In the present study, oscillations of a weak normal shock-wave in a supersonic diffuser were measured by a Line Image Sensor(LIS), and they were compared with the data of the wall pressure fluctuations at the foot of the shock-wave interacting with the wall boundary layer. LIS was incorporated into a conventional schlieren optical system and its signal, instantaneous displacement of the interacting shock-wave, was analyzed by a statistical method. The results show that the displacement of an oscillating shock-wave increase with the upstream Mach number and the dominant frequency components of the oscillating shock-wave are below 200 Hz. Measurements indicated that shock-wave oscillations may not entirely be caused by the boundary layer separation. The statistical properties of oscillations appeared, however, to be significantly affected by shock-induced separation of turbulent boundary layer.