• Coupled systems mechanics
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• v.9 no.5
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• pp.455-471
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• 2020

This paper presents the results of the study of vertically natural frequency of tractor tires are effected by changing different ground contacts and inflation pressures using the Free Decay Method. The results show that the natural frequencies of the tire are not affected while the vertical acceleration increased strongly due to the increase of inflation pressure when the tire performs free decay vibration on rigid ground. In addition, the number of natural frequency peaks of the tire also increases with increasing tire inflation pressure. On the other hand, the natural frequencies of the tractor tire increases strongly while the vertical acceleration decreases slightly with the increase of tire inflation pressure as the tire performs free decay vibration on soft soil. Further, the natural frequencies of tire-soil system are always higher than that of tire only, and it changed with changing the soil depth. Results also show the natural frequency of tire and tire-soil system is in the range of 3.0 to 10.0 Hz that lie within the most critical natural frequency range of the human body. These findings have to be mentioned and used as design parameters of the tractor suspension system.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1055-1060
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• 2009

Noise is one of the major environmental problems in human life. But hot water distributers with the flow rate control valve bring about often noise according to the heating control condition in residential buildings. The sound power level increased as the flow rate and pressure difference increased. And thus, experimental analyses for the flow rate control and the pressure difference control were carried out in this study to reduce the noise emitted from the flow rate control valve. As the results, the flow rate control method using a SMA(Shape Memory Alloy)-valve and the flow rate control system using a pressure difference sensor can be expected to control noise in the region of below 50 dB of sound power level.

• Journal of the Korean Society for Library and Information Science
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• v.31 no.3
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• pp.209-237
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• 1997

The main purpose of this study is to find the difference of information searching behaviours consist of information pursuit cognition and searching character by time pressure of researchers. The majar findings and result by time pressure of researchers are summarized as follows : In terms of information retrieval systems, according to the time pressure, there is a significant difference in recall, precision and diversity. In terms of main used material, there is a significant difference in a book, a research report, and a Journal. In terms of resource types, there is a significant difference in both record and human resource. Also, in terms of searching behaviours, there is a difference to spend time for information collection and information searching strategy, and to decide information searching method and degree of searching.

• Fibers and Polymers
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• v.7 no.4
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• pp.389-397
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• 2006

The beneficial effects of graduated compression stockings (GCS) in prophylaxis and treatment of venous disorders of human lower extremity have been recognized. However, their pressure functional performances are variable and unstable in practical applications, and the exact mechanisms of action remain controversial. Direct surface pressure measurements and indirect material properties testing are not enough for fully understanding the interaction between stocking and leg. A three dimensional (3D) biomechanical mathematical model for numerically simulating the interaction between leg and GCS in dynamic wear was developed based on the actual geometry of the female leg obtained from 3D reconstruction of MR images and the real size and mechanical properties of the compression stocking prototype. The biomechanical solid leg model consists of bones and soft tissues, and an orthotropic shell model is built for the stocking hose. The dynamic putting-on process is simulated by defining the contact of finite relative sliding between the two objects. The surface pressure magnitude and distribution along the different height levels of the leg and stress profiles of stockings were simulated. As well, their dynamic alterations with time processing were quantitatively analyzed. Through validation, the simulated results showed a reasonable agreement with the experimental measurements, and the simulated pressure gradient distribution from the ankle to the thigh (100:67:30) accorded with the advised criterion by the European committee for standardization. The developed model can be used to predict and visualize the dynamic pressure and stress performances exerted by compression stocking in wear, and to optimize the material mechanical properties in stocking design, thus, helping us understand mechanisms of compression action and improving medical functions of GCS.

• Fire Science and Engineering
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• v.30 no.2
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• pp.56-61
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• 2016

Recently, Since buildings are bigger and higher, the damage of human life can be increased by fire flame and smoke in fire. Smoke control system is necessary to decrease this damage. Therefore, Air supply pressurization smoke control system is applied to vestibule of escape stairway. NFSC requires pressure differential of above 40 Pa, but pressure differential is excessively overpressure in the field. It is known that the cause of this over pressure differential is much leakage of damper. Over pressure differential can bad effect to escaper by pressurizing the door. Analyze the real leakage of damper by increasing the number of dampers operation for identifying this problems. The result of testing, the leakage has difference between new dampers and increased the number of operation dampers. As the static preassure increase, the leakage difference increase. Comparison with preceding study, this result has similar linear tendency.

• Journal of Biomedical Engineering Research
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• v.38 no.3
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• pp.111-115
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• 2017

Blood pressure is one of the important vital signs for monitoring the medical condition of a patient. Automated NIBP(non-invasive blood pressure) monitoring devices calculate systolic and diastolic blood pressures from the oscillation in cuff pressure caused by a pulsation of an artery. To validate the NIBP devices, we developed a simulator to supply the oscillometric waveforms obtained from human subjects. The simulator provided pressure pulses to device-under-test and device readings were compared to the auscultatory references. Fully automated simulation system including OCR(optical character recognition) were developed and used for NIBP monitoring devices. The validation results using the simulator agreed well with previous clinical validation. More validation studies using the standardized oscillometric waveforms would be required for the replacement of clinical trials to validate a new automated NIBP monitoring device.

• Journal of the Korean Society of Clothing and Textiles
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• v.9 no.2
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• pp.45-55
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• 1985

The main purpose of this study is to investigate the suitability of Boesun (the Korean Socks) to the foot. In order to find the problem of Boesun, I made up the questionnaire. The suitabltity of Boesun to the foot was experimented by 'the replica method', 'the fuse method' and 'the deform painting method'. The pressure of Boesun to the foot was measured by utilizing a human sensitivity as a sensor. The results were as follows. 1. In the questionnaire, the fore part of Boesum was uncomfortable by the pressure. 2. The surface area of Boesun was generally smaller than the surface area of the foot, but the ratio of two surface area related closely to the individual. 3. At the cross-sections from No. 1 to No. 10, the breadth of the worn Boesun was smaller than the breadth of the foot. Because of the smaller breadth of the worn Boesun, the foot was get the pressure at the fore part of Boesun. This result accorded with the result of the questionnaire. 4. The location of the deformation by 'deform painting method' was almost the fore part of Boesun. 5. The pressure of Kwon's Boesun was 2.57$\~$2.99kg, the pressure of Kim's Boesun was 1.31$\~$1.74 kg and the pressure of Lee's Boesun was 3.42$\~$3.88kg. Compared with the distribution chart of the pressure, Kwon's Boesun was involved the back part of 'slightly pressured' and the fore part of 'pressured', Kim's Boesun was involved the fore part of 'slightly pressured' and Lee's Boesun was involved the middle part of 'pressured'.

• Korean Journal of Medicinal Crop Science
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• v.16 no.6
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• pp.439-445
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• 2008

This study was performed to investigate a methodology of improving immune activities of Berberis koreana Palibin by ultra high pressure on low temperature extraction process. Extraction yield was enhanced up to more than 35% by above process, compare to the control and extraction average. The cytotoxicity on human kidney cell (HEK293) was showed below 20.4%, 21.6% in adding 1.0 mg/ml of the highest concentration. Generally, the extracts by ultra high pressure extraction process showed less toxicity about 5% than the other processes. It could tell that toxic materials that existing in the plant could be reduced or broken by ultra high pressure process due to can be broken bond such the hydrogen bond, the electrostatic bond, the van der Waals bond, and the hydrophobic bond, can be broken by high pressure. The result could be employed to develop a new type of functional food from B. koreana Palibin by low temperature high pressure process.

• Korean Journal of Acupuncture
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• v.19 no.1
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• pp.47-56
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• 2002

The frequency of the hypertension is increasing as the life level is improved and an average span of the life is extended since we approached modern stage. The hypertension is also dangerous disease which raises fatal complication for example with the bleeding aproplexy and the ischemic attack. The medicinal treatment about the hypertension is required patients to take continually. The acupuncture have been introduced because a medicine-chemical treatment hasn't good influence on the human body. It recently has been processed that studies acupuncture effect for blood pressure and have been found out that blood pressure go down. The object of this study observe the effect of LR3 acupuncture on hypertension in Renal Hypertension RAT induced by 2K1C. The 2K1C model was based on renin-angiotensin system. We put the silver clip in renal artery to induce renal hypertension. We try to observe that LR3 acupuncture influence on the blood pressure and c-fos expression in CVLM, NTS, RVLM. In results, the blood pressure was decreased during acupuncture than before acupuncture, after acupuncture. The heart rate was also decreased during acupuncture than before acupuncture, after acupuncture. The LR3 acupuncture significantly effects on blood pressure and heart rate (P<0.05). The increased expression of c-fos was shown in CVLM, NTS, but not in RVLM. In conclusion, LR3 was relived the action of control upon the hypertension and related with medulla, particularly CVLM, NTS. It needs to be closely examined pharmacological mechanism and studied combination with other acupoints.

• Journal of the Korea Safety Management & Science
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• v.16 no.2
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• pp.211-216
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• 2014

Using a high-rise building water piping after hydrostatic test of the reliability of the leak to be completed if the pressure is maintained until the leak is not commercially available considered. Due to the nature of high-rise buildings and the construction period will take several years from the lower levels of use of the water supply and fire fighting water pipe construction is in progress, the order of which I do most of the first pipe to the construction and more than three years. So kind of riser pipe is complete, install the valve in the basement by installing an automatic pump to maintain a constant pressure after hydrostatic test and after each floor plumbing piping is complete, the progress of the hydrostatic test without undergoing a separate branch pipe the valve is opened automatically when the number of the pressing pressure of the structure. I kind of do and keep working pressure of pipe until the completion of the construction work to keep the damage to human error when it is intended to prepare. In winter, the frost protection and an alternative to drainage water pipe is damaged or deformed, even if unaware of the finishing work to the building, the use of the damage caused by a leak in a after construction of finish work to be expected. Alternative to reduce this damage if the pressure test without fear of freezing to help maintain long-term commercial pressures may be considered.