• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.10 s.253
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• pp.1019-1025
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• 2006

Numerical simulations were conducted on the gerotor type oil pump. Three oil pump models having different port and groove shape were considered. Firstly, two original models (baseline & variant.1 model) were simulated in order to validate the accuracy of the simulation results and to better understand the flow characteristics in the pump. It was found that the cavitation phenomenon as well as the teeth tip leakage is most important parameter on the pump performance. Based on the simulation results of the original models, final model (variant.2 model) which has improved port shape and pressure relief valve is suggested to enhance pump performance and to reduce driving torque. The volumetric efficiency and the hydraulic torque of the Variant.2 model is improved 4% and reduced 6.1% each at 2000RPM in experiment.

• Journal of Chest Surgery
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• v.16 no.2
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• pp.164-169
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• 1983

The patient in whom corrected transposition of the great vessels is an isolated congenital anomaly has a physiologically normal circulation. A 19 year old male was perforemd with surgical correction for congenitally corrected transposition of great arteries (SLL) associated with ventricular septal defect (type I) and severe pulmonary stenosis. After right sided ventriculotomy, ventricular septal defect was repaired with Dacron patch and to provide adequate relief of severe valvar stenosis of pulmonary artery, valvulotomy was done. On immediate postoperative period, complete heart block and lower cardiac output state were ocurred, but adequate blood pressure could be maintained under using of inotropic agent and temporary pace-maker.

• Progress in Superconductivity and Cryogenics
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• v.16 no.3
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• pp.15-20
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• 2014

The heavy ion accelerator that will be built in Daejeon, Korea utilizes superconducting cavities operating in 2 K. The cavities are QWR (quarter wave resonator), HWR (half wave resonator), SSR1 (sing spoke resonator1) and SSR2. The main role of the cryomodule is supplying thermal insulation for cryogenic operation of the cavities and maintaining cavities' alignment. Thermal and structural consideration such as thermal load by heat leak and heat generation, cryogenic fluid management, thermal contraction, and so on. This paper describes detailed design considerations and current results have being done including thermal load estimation, cryogenic flow piping, pressure relief system, and so on.

• Journal of Korean Neurosurgical Society
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• v.47 no.2
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• pp.140-142
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• 2010

Acupuncture appears to be a clinically effective treatment for acute and chronic pain. A considerable amount of research has been conducted to evaluate the role that acupuncture plays in pain suppression; however, few studies have been conducted to evaluate the side effects of the acupuncture procedure. This case report describes a suspected postdural puncture headache following acupuncture for lower back pain. Considering the high opening pressure, cerebrospinal fluid leakage, and the patient's history of acupuncture in the lower back area, our diagnosis was iatrogenic postdural puncture headache. Full relief of the headache was achieved after administration of an epidural blood patch.

• The Korean Journal of Pain
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• v.24 no.1
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• pp.57-60
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• 2011

Pulsed radiofrequency (PRF) treatment of nervous tissue has been proposed as a less neurodestructive technique alternative to continuous RF heat lesioning. Recently, clinical reports using PRF have shown favorable effects in the treatment of a variety of focal pain areas, even in non-nervous tissues; however, the mechanism of effect underlying this treatment to non-nervous tissue remains unclear. We report the case of a 67-year-old male who presented with pain reliving point in the posterior neck. The patient had pain in the posterior neck for 3 years. The pain subsided with pressure applied to a point in the posterior neck. There were no specific abnormal findings on laboratory testing and radiologic examinations. After PRF treatment to the pain-relieving point, he had pain relief which lasted more than 5 months.

• Journal of the Korean Society of Radiology
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• v.16 no.6
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• pp.787-797
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• 2022

The purpose of this study was to confirm the reduction of pain and symptom relief of Parkinson's disease by vertically stimulating the spine through the application of a mechanical bed capable of thermal and massage stimulation. For this purpose, after confirming the segmental motion of the spine due to the use of a medical combination stimulation bed for Parkinson's disease patients, VAS, ODI, gait ability, and spiral drawing tests were performed, and the relationship between the variables was identified. In the 10-day visual analog scale and evaluation of low back pain dysfunction, the average trend of decreasing after bed use was confirmed. For walking ability, a decrease in the moving time and an increase in the moving distance were observed. In the spiral drawing test, the mean test time after using bed was significantly lower than before. As a result, it suggested the possibility of using it as an auxiliary method for recovery and pain relief of Parkinson's disease patients due to spinal segmental movement with mechanical heating and massage. However, this study is a preliminary study, and there is a small number of subjects, so additional research is needed that considers the number and condition of future subjects in detail.

• Plant Journal
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• v.15 no.4
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• pp.36-42
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• 2019

In recent, according to the tightening of environment regulation policy, the height of the site of the power plant is increased and the length of the cooling water pipe is increased. This has a serious impact on the stability of the plant. This study analyzes the transient phenomenon using LIQT 7.2, an unsteady state one-dimensional analysis software, to secure the stability of 1,000 MW high-capacity coal-fired power plant cooling water system with high head. To prevent water hammer, The effects on performance characteristics were predicted by individual and combination application. The surge pressure of the cooling water which occurs when the pump was stopped without installing the anti-surge devices was the largest at the pump outlet side. The most effective and simple way to reduce surge pressure in these cooling water systems is to combine a vacuum breaker with a hydraulic non-return valve, which is an essential device for pump protection.

• Research in Community and Public Health Nursing
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• v.12 no.2
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• pp.375-389
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• 2001

The purpose of this study was to evaluate the effect of Self-foot Reflex Massage (SRM) programme on the physical condition and anxiety level of hypertension workers. The research was designed in the pre and post-test. Sample test was done in five workers with essential hypertension. They were divided in two groups:- Group A and Group B. The Self-foot Reflex Massage (SRM) was applied three times a week for Group A and five times a week for Group B. The SRM was given in 40 minutes each time for 4 weeks from the 1st of January to the 30th of April in 2001. In order to evaluate the effect on SRM. blood pressure, total cholesterol, triglyceride, HDL cholesterol and LDL cholesterol were measured as physical parameters and state trait anxiety inventory was used twice each time between before and after the exercise. The collected data was analysed by Mann-Whitney test with SPSS program. The results were as follows: 1. Average age for the subjects were 39.8 (ranged from thirty-two to fifty-three) and average period of hypertension history was 42 months (ranged from twenty to eighty-four). 2. There was no significant difference between two examined groups in blood pressure. But, there was a significant difference in SRM of pre and post-test for two groups. 3. There was no significant difference in blood cholesterol between two groups and between pre and post-test. 4. State trait anxiety showed significant difference between pre and post-test except the results between two groups. This result suggests that SRM is effective on the decrease of systolic and diastolic pressure and the relief of state trait anxiety except for the blood cholesterol. Therefore, blood cholesterol is needed further evaluation in large subjects and longer period. Further research is regarded as necessary to evaluate and to compare the precise effects of SRM on the foot reflex massage (FRM) in anxiety.

• Journal of Biosystems Engineering
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• v.27 no.1
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• pp.11-18
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• 2002

One of the major obstructing factors against managing dairy farm in Korea has been a shortage of roughage supply, which resulted in excessive abuse of concentrate feed. In order to solve this problem, production of the wrap silage by the winter cereal forages raised in the fallow paddy field is strongly recommended in Korea. The main objective is to develop a tractor attached round bale wrapper which can process the silage by wrapping the round bales with thin plastic films. This is the first half of the study which is divided by two parts. In this first part, bale wrapping process was analyzed, and based on this results the followings were designed, developed and tested. 1. Bale wrapper which haying the maximum capacity of 1 ton bale with various functions such as loading, wrapping, discharging the round bales and supplying and cutting wrap films was designed. 2. An actuator and its hydraulic circuit of each process were developed and tested. 3. Also, the variations of hydraulic pressure and engine speed were investigated by operating bale wrapper developed. In this test, maximum pressure of the hydraulic circuit for the bale wrapping was 130 kg/㎠ when it raised the bale, which was quite below the relief pressure of 170 kg/㎠ of hydraulic circuit. In the engine speed test, speed drop was 20∼67 rpm, which meant that there was no over-load operation. Therefore, the experiment proved that developed hydraulic circuit and mechanism is stable in bale wrapping operation

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.1
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• pp.25-36
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• 2021

Hydrogen in hydrogen-electric vehicles has a wide range of combustion and explosion ranges, and is a combustible gas with a very fast flame propagation speed, so it has the risk of leakage, diffusion, ignition, and explosion. The fuel tank has a Thermally active Pressure Relief Device (TPRD) to reduce the risk of explosion and other explosions, and in the event of an accident, hydrogen inside the tank is released outside before an explosion or fire occurs. However, if an accident occurs in a semi-closed space such as an underground parking lot, the flow of air flow is smaller than the open space, which can cause the concentration of hydrogen gas emitted from the TPRD to accumulate above the explosion limit. Therefore, in this study, the leakage rate and concentration of hydrogen over time were analyzed according to the diameter of the nozzle of the TPRD. The diameter of the nozzle was considered to be 1 mm, 2.5 mm and 5 mm, and ccording to the diameter of the nozzle, the concentration of hydrogen in the underground parking lot increases in a faster time with the diameter of the nozzle, and the maximum value is also analyzed to be larger with the diameter of the nozzle. In underground parking lots where air currents are stagnant, hydrogen concentrations above LFL (Lowe Flammability Limit) were analyzed to be distributed around the nozzle, and it was analyzed that they did not exceed UFL (Upper Flammability Limit).