• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.929-933
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• 2003

Internal defects of thin pressure vessel used in the power plants or the chemical plants may be created and grow due to corrosion or creep fatigue to reduce the strength and cause critical failure during operation. Therefore it is very important to detect this defect at the early stage. For this purpose, non-destructive, non-contact and highly sensitive method should be considered for on-line application. In this paper, a laser shearographic interferometer is applied to inspect circular defects and notch defects existed inside of thin pressure vessel under the presence of pressure up to 3 times of atmospheric pressure. The influences of the defect shape and size as well as the internal pressure to the characteristic pattern in the shearography fringe are investigated, and the quantitative evaluation of the defect size is tried. Also the experimental results are compared with the destructive test results to show the applicability of this method to the quantitative evaluation of internal defects in the thin pressure vessel.

• Journal of the Korean Society for Railway
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• v.12 no.2
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• pp.309-314
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• 2009

When a train enters into a tunnel, a compression wave is generated by a front nose and a expansion wave is generated by a rear tail respectively. The interaction between pressure waves and the train makes the internal and external pressure of the train change dramatically. In this paper, we had measured the internal and external pressure variations of TTX and analyzed the pressure variations as the tunnel length. Also, the rate of internal pressure variations were investigated with the current airtight condition of TTX. In short tunnels, the internal and external pressure variation were not large because the superposition of pressure waves was not happened. In long tunnels, however, the rapid and large pressure variations were shown because of the superpositions between the same sort of pressure waves, such as expansion wave and expansion wave or compression wave and compression wave. In specific length tunnels, the pressure variation and the pressure variation rates were largely lessened because the compression wave and expansion wave were superposed.

• Wind and Structures
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• v.16 no.1
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• pp.47-60
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• 2013

A dominant opening in a windward wall, which generates large internal pressures in a building, is a critical structural design criterion. The internal pressure fluctuations are a function of the dominant opening area size, internal volume size and external pressure at the opening. In addition, many buildings have background leakage, which can attenuate internal pressure fluctuations. This study examines internal pressure in buildings for a range of dominant opening areas, internal volume sizes and background porosities. The effects of background porosity are incorporated into the governing equation. The ratio of the background leakage area $A_L$ to dominant opening area $A_W$ is presented in a non-dimensional format through a parameter, ${\phi}_6-A_L/A_W$. Background porosity was found to attenuate the internal pressure fluctuations when ${\phi}_6$ is larger than 0.2. The dominant opening discharge coefficient, ${\kappa}$ was estimated to lie between 0.05 to 0.40 and the effective background porosity discharge coefficient ${\kappa}^{\prime}_L$, was estimated to be between 0.05 to 0.50.

• Wind and Structures
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• v.28 no.2
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• pp.89-97
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• 2019

The non-linear equations governing wind-induced internal pressures for a two-compartment building with background leakage are linearized based on some reasonable assumptions. The explicit admittance functions for both building compartments are derived, and the equivalent damping coefficients of the coupling internal pressure system are iteratively obtained. The RMS values of the internal pressure coefficients calculated from the non-linear equations and linearized equations are compared. Results indicate that the linearized equations generally have good calculation precision when the porosity ratio is less than 20%. Parameters are analyzed on the explicit admittance functions. Results show that the peaks of the internal pressure in the compartment without an external opening (Compartment 2) are higher than that in the compartment with an external opening (Compartment 1) at lower Helmholtz frequency. By contrast, the resonance peak of the internal pressure in compartment 2 is lower than that in compartment 1 at higher Helmholtz frequencies.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.2
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• pp.191-199
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• 1992

This paper presents in experimental study of the dynamic internal pressure within an oil hydraulic vane pump. The measurements of the dynamic internal pressures near the vane of a pressure balance type of an oil hydraulic vane pump with intravanes has been made to provide the essential information for the study of the pump dynamics and control, the pump design and the analysis of tribological problems in the sliding components. The influences of the discharge pressure and rotating speed of the vane on the dynamic pressure in four chambers surrounding a vane have been investigated. The results indicate that the surge pressures of the chambers at the instant moment of discharge and closure are affected by the rotating speed. The pressure in the intravane chamber maintains almost constant values, which remarkably effects the pulsating discharge pressure.

• The Journal of Internal Korean Medicine
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• v.31 no.2
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• pp.388-394
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• 2010

Objectives : This study reports two cases of grade four pressure ulcer patients mainly treated by pharmacopuncture Soyeom and Taklisodok-eum. Methods : Two patients with grade four pressure ulcers at the oriental medicine hospital of Woosuk University were treated by pharmacopuncture Soyeom and herbal medicine Taklisodok-eum. Soyeom was treated once a day and Taklisodok-eum was given three times a day. We then observed the patients' appearances of pressure ulcer and changes of blood test results. Results and Conclusions : After ten days or three months each, wound sizes were reduced, tissue regeneration was accelerated and blood tests were improved. In conclusion, it is our belief that pharmacopuncture and herb medicine are effective to treat grade four pressure ulcers, and future studies will be required to ascertain this method on grade four pressure ulcers.

• The Journal of Internal Korean Medicine
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• v.42 no.2
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• pp.122-130
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• 2021

The purpose of this study is to report the effect of Korean medicine treatment on a pressure sore in a stroke patient. An 86-year-old female patient diagnosed with spontaneous intracerebral hemorrhage in the right basal ganglia had symptoms of left hemiparesis, dysphagia, and a 4.5-cm-by-2.5-cm left trochanteric pressure sore. Clinical outcomes were measured using the National Pressure Ulcer Advisory Panel (NPUAP) pressure injury stages, the Agency for Health Care Policy and Research (AHCPR) pressure ulcer stages, and the Braden scales. Treatment with Korean medicine, including acupuncture, herbal medicine, and dressing therapy, significantly improved the trochanteric pressure sore, as reflected by a NPUAP stage change from III to I, an AHCPR stage change from III to I, and a Braden scale change from 13 to 18. These findings suggest that Korean medicine treatment may be effective to treat pressure sores in stroke patients.

• The Journal of Internal Korean Medicine
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• v.22 no.4
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• pp.621-625
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• 2001

Objectives: We examined if their hematological status could be changed by blood loss in patients treated with bleeding pressure therapy. Methods: The patients were divided into two groups as follows: The Subject group(B) were 42 cases treated with bleeding pressure therapy. The Control group(N) were 43 cases treated with negative bleeding pressure therapy, We checked CBC & differ cell count of two groups. Results: The means of RBC, Hb count and Hct were slightly decreased after 1 week. but they were recovered after 2 weeks. Conclusions: These results indicate that Bleeding Pressure Therapy don't reduced RBC, Hb count and Hct in Patients.

• Wind and Structures
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• v.21 no.1
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• pp.1-23
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• 2015

Wind tunnel testing of a low-rise building with openings (holes) of different sizes and shapes on a roof corner is conducted to measure the internal and external pressures from the building model. Detailed analysis of the testing data is carried out to investigate the characteristics of the internal and external pressures of the building with different openings' configurations. Superimposition of the internal and external pressures makes the emergence of positive net pressures on the roof. The internal pressures demonstrate an overall uniform distribution. The probability density function (PDF) of the internal pressures is close to the Gaussian distribution. Compared with the PDF of the external pressures, the non-Gaussian characteristics of the net pressures weakened. The internal pressures exhibit strong correlation in frequency domain. There appear two humps in the spectra of the internal pressures, which correspond to the Helmholtz frequency and vortex shedding frequency, respectively. But, the peak for the vortex shedding frequency is offset for the net pressures. Furthermore, the internal pressure characteristics indirectly reflect that the length of the front edge enhances the development of the conical vortices.The objective of this study aims to further understanding of the characteristics of internal, external and net pressures for low-rise buildings in an effort to reduce wind damages to residential buildings.

• The Journal of Internal Korean Medicine
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• v.25 no.2
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• pp.314-319
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• 2004

Objective : This study was designed to evaluate the effects of oriental medicine therapy on a normal pressure hydrocephalus patient. Methods : The clinical data was analyzed on a patient with normal pressure hydrocephalus whose main symptoms were dementia, gait disturbance and urinary incontinence. The patient was admitted to the internal medicine department of Dong-shin University Oriental Hospital from December 7, 2002, and remaind until January 20, 2003. He was treated with herbal medicine(Yukmijiwhangtang), acupuncture and moxa therapy. Results : After treatment, improvement was seen in dementia, gait disturbance, and urinary incontinence. Conclusions : The study suggests that oriental medicine therapy is significantly effective on the treatment or normal pressure hydrocephalus.