• Journal of ILASS-Korea
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• v.13 no.4
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• pp.173-179
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• 2008

The current machinery and tools of secondary channel of the nuclear power plants were produced in the carbon-steel and low-alloy steel. What produced with the carbon-steel occurs wall thinning effect from flow accelerated corrosion by the fluid flow at high temperature, high pressure. Several nuclear power plants in Korea have experienced wall thinning damage in the area around the impingement baffle-installed. Wall thinning by flow accelerated corrosion occurs piping system, the heat exchanger, steam condenser and feedwater heaters etc,. Feedwater heaters of many nuclear power plants have recently experienced sever wall thinning damage, which will increase as operating time progress. This study describes the comparisons between the numerical results using the FLUENT code and experimental data of down scale model.

• Biomedical Science Letters
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• v.19 no.1
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• pp.55-60
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• 2013

This study was to know the effects of massage on the back region in order to reduce stress in middle age women. To investigate the effects of massage to the stress levels of middle aged women, we evaluated blood pressure (BP), heart rate variability (HRV), and ultrasonography before and after back massage. The blood pressure after massage was reduced when compared to that of pre-massage. The HRV spectrum analysis was used Frequency domain analysis such as Mean HRV, normalized low frequency (norm LF), norm high frequency (norm HF), and LF/HF ratio. Post-massage BP tended to be low, but not statistical significant. After Massage, the Mean HRV, norm LF, and LF/HF ratio were significantly reduced, while norm HF was significantly increased as compared with pre-massage. The muscle layer and fat layer were significantly diminished by massage. The study was suggested that massage may be an effective treatment for relief of stress.

• Sleep Medicine and Psychophysiology
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• v.12 no.2
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• pp.93-97
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• 2005

Nasal obstruction may cause or aggravate sleep disordered breathing but exact pathogenesis is not clear. The possible mechanism could be combination of alteration in upper airway aerodynaimcs, loss of nasal reflex or sensation, effect of mouth opening, and a genetic predisposition. Anatomical narrowing of nasal airway cause more rapid airflow and induce more negative inspiratory air pressure. So, it increases collapsibility of pharyngeal airway. Loss of nasal sensation to airflow block nasal reflex. Mouth opening decreases the activity of pharyngeal airway dilator muscles and narrowing the pharyngeal airway may occur. The treatment of nasal obstruction should be done according to the cause. The causes of nasal obstruction are various from problems of external nasal opening to nasopharynx. Relief of nasal obstruction may not cure sleep disordered breathing always. In some mild obstructive sleep apnea patients, treatment of nasal obstruction only may cure sleep disordered breathing. In some severe sleep apnea patients, treatment of nasal obstruction may increase compliance of continous nasal positive airway pressure.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.365-366
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• 2015

This paper describes the analysis on thermo-mechanical characteristics of underground cable termination. Specially, the interface pressures between stress relief cone and XLPE insulation were analysed according to the change of conductor temperature and ambient temperature. This interface pressures were measured by real test with current transformer and chamber and the interface pressure was changed with conductor and ambient temperature. This paper will continue to perform the test with various cases, then the relation between low interface pressure and breakdown will prove with test results in the near future.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.11
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• pp.122-132
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• 1999

This study describes a dynamic model of the hydroforming process which is used for precision forming of sheet metals. To help the controller design for the control of the forming pressure needed for this process as well as to investigate the effect of system parameters on the dynamic behavior, dynamic modeling is performed with emphasis on hydraulic servo system which actuates the forming machine. Since the model contains several unknown parameters, these were estimated via a least square parameter identification method. Based upon the identified model, a series of simulations were performed for various operating conditions. The results were compared with those of the experiments to verify the validity of the proposed model. The comparison study shows that the proposed dynamic model can describe dynamic behavior of the forming pressure of the hydroforming process to desirable accuracy.

• Journal of Korean Biological Nursing Science
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• v.22 no.4
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• pp.271-278
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• 2020

Purpose: This study was performed to identify the risk factors for oral mucosa pressure ulcer development in intubated patients in adult intensive care unit. Methods: Comparative descriptive study design using prospective observational design and medical record review was used. The inclusion criteria of case was that a) patients of 18 years in their age, b) patients with endotracheal tube. Data of 34 patients were analysed. Descriptive statistics, chi-square test, Fisher's exact test, Mann-whitney test, Spearman's rho correlation coefficients, and multiple logistic regression analysis were used. Resampling methods such as bootstrap was used in this study because of small number of patients. Results: Oral mucosa pressure ulcer developed in 44.1% of the intubated patients. The risk factors of oral mucosa pressure ulcer were steroid use, biteblock use and serum albumin level. Compared to the non-user of steroid, user of steroid had 32.59 times (95% CI: 1.47-722.44) higher risk of developing oral mucosa pressure ulcer. The user of biteblock had 18.78 times (95% CI: 1.00-354.40) and albumin level had 0.03 times (95% CI: 0.00-0.80) higher risk of oral mucosa pressure ulcer incidence. Conclusion: Based on the results of this study, tailored pressure relief strategies considering sex and therapeutic condition should be provided to decrease oral mucosa pressure ulcer.

• The Korean Journal of Pain
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• v.1 no.1
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• pp.98-102
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• 1988

In order to control the pain after hemorrhoidectomy and anal fistulectomy, 6 mg of 0.5% hyperbaric tetracaine without(control, group I) or wilt 0.3 mg(group II) or 0.5 mg (group III) of 0.1% morphine was injected with a 22 gauge spinal needle into the subarachnoid space through L 3-4 interspace of patients in lateral position. About 30 minutes in Fowler' sposition after injection, operation was performed in lithotomy position. All the patients who ha4 morphine showed remarkable relief of postoperative pain for an average of 27 hours. However, the dosage(0.3 or 0.5 mg) of morphine administered did not affect the duration of pain relief. Blood pressure, pulse rate and pupil size were unchanged in all patients. Dysuria after block developed for on average of 5,6, 13.2 and 14.6 hours in group I, II and III respectively. Most of these cases required urethral catheterization. Minor complications such as nausea, vomiting, itching, fever, burning sensation and paresthesia were observed 16.7, 20 and 20% of cases in group I, II and III respectively; however, no treatment was required.

• The Korean Journal of Pain
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• v.6 no.1
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• pp.109-116
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• 1993

In March of l992, We performed two intentional total spinal blocks for the relief of pain. This was for 2 cases of post-traumatic cervical syndrome whose various symptoms were chronically unresponsive to the usual conservative treatments. We regularly checked the blood pressure, pulse rate, oxygen saturation and observed clinically the changes of respiration, consciousness, lid and light reflexes during the total spinal block. Pain relief was evaluated by using the Visual Analog Scale which is designed to measure the subjective intensity of pain. The results were as follows; 1) The effectiveness of total spinal block was 60% in case 1, 40% in case 2. 2) We observed two complications from the procedure. Firstly during the block, these were transient periods of hypotension. Following the block, accidental procedures related direct neural trauma resulted in anterior chest wall pain. In conclusion we believe that total spinal block is a satisfactory and reliable method for the treatment of post-traumatic cervical syndrome.

• Biomedical Science Letters
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• v.26 no.4
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• pp.310-318
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• 2020

The sciatic nerve is the largest nerve among the peripheral nerves, and the damage to the sciatic nerve is caused by mechanical and physical pressure. This is an important disease that consumes a lot of time and money in the treatment process. Among them, research on relieving nerve pain caused by damage to the peripheral sciatic nerve has been made efforts to prevent and treat this disease through various methods such as drugs, natural products, electrical stimulation, exercise therapy, and massage. Existing treatments are not very effective in neurological pain, and countermeasures are needed. Forsythia Fructus, used in this study, has been used as a therapeutic agent for infectious diseases and a pain reliever for cancer from the past, and in past studies, it has been known to properly control the inflammatory response. In this study, rengyolone, a physiologically active substance of Forsythiae Fructus, was administered to rats that caused chronic left nerve pain to verify the pain relief effect. As a result of the experiment, it was found that mechanical pain and cold stimulation pain were significantly reduced in the rengyolone-treated group compared to the non-administered group. In addition, it was found that nerve growth factor (NGF) mRNA expression was significantly reduced and Cyclin-dependent kinase 2 (Cdc2) expression was increased in the rengyolone administration group. This increase in NGF expression is thought to be related to rengyolone's anti-inflammatory regulatory mechanism. It is expected that the reduced NGF was directly involved in pain relief.

• Journal of the Korean Geotechnical Society
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• v.25 no.1
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• pp.21-29
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• 2009

On plane strain condition, many researchers have investigated the earth pressure according to the shape of wall, and standardized method has been applied to the design of the retaining wall. But on cylindrical diaphragm wall, at-rest earth pressure has been generally used. Even though this method is on conservative side, it may lead to over-design. In this paper, the application of convergence confinement method to the calculation of the earth pressure acting on the cylindrical diaphragm wall of a shaft was suggested. In addition, a model test was carried out to investigate the distributions of earth pressure. Model test results show that the earth pressures of diaphragm wall are about 1.4 times larger than active earth pressure and about 0.8 times less than at-rest earth pressure.