• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.109-116
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• 2012

A vent-relief valve performs as a safety-valve assembly for liquid propellant feeding system of space launch vehicle, which relives pressurant propellant tanks during the filling and the flight. At vent mode, valve is opened and closed by driving pneumatic pressure, and at relief mode, valve is automatically operated to set relief pressure. In this study, we have analyzed a basic layout of vent-relief valve which is designed using foreign LVs(Saturn) to satisfy requirements of Korean Space Launch Vehicle. The simulation model of vent-relief valve is designed by using the AMESim code to verify design parameters and evaluate pneumatic behaviors of valve. In this study, we performed dynamic characteristic simulations on design parameters. And we could predict opening/closing time and pressures, operating performances on design parameters. Using this results, we could suggest detail design and boundary conditions of design.

• Macromolecular Research
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• v.16 no.5
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• pp.434-440
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• 2008

Three-armed, star-shaped molecules containing 4-(N,N-diphenyl)amino-4'-nitroazobenzene chromophores were synthesized to study the diffraction behavior after inscribing surface relief gratings. The two molecules differed in terms of their mode of chromophore attachment to the core. In compound 5, they were bound to the core laterally through alkylene spacers, whereas the chromophores were tethered perpendicularly to the core in compound 4. Although 60 wt% of the polar azobenzene chromophores was comprised of large molecules, no aggregation behavior was observed in the absorption spectra of the thin films. The surface relief gratings were elaborated on the surface of the molecular films by the two-beam interference method. The dynamics of grating formation were studied in terms of the diffraction efficiency using two different film samples made up of two star-shaped molecules. The maximum diffraction efficiency of D-$(ENAZ)_3$, compound 4, was measured to be about 30%, which was significantly high. The mode of chromophore attachment affected the dynamic properties of the diffraction gratings.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1051-1053
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• 2017

We have designed the vent relief valve to set bi-level safety pressure for oxidizer tank. The minimum cavity volume was calculated to reduce the pressure deviation, and the valve operation characteristics was analyzed by using modeling. We have a plan to manufacture the validation model based on the analysis results.

• The Journal of Korean Physical Therapy
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• v.26 no.5
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• pp.331-343
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• 2014

Purpose: The purpose of this study is to assess the effectiveness of short-wave therapy (SWT) for treatment of knee osteoarthritis (OA) as compared to placebo and control, and to assess the question of whether the effects are related to the mode, dosage, and application method. Methods: We searched randomized, placebo-controlled trials using electronic databases. We also manually reviewed sources in order to identify additional relevant studies. Results: Eight studies (597 participants) with OA were included in the meta-analysis. Pulse SWT had a significant effect on pain relief compared with control treatment, while did not favour compared with the placebo group. Pulse SWT had a significant effect on functional improvement compared with control and placebo treatment. Continuous SWT had no effect on pain relief and functional improvement. Capacitive SWT a significant effect on pain relief, functional improvement, and muscle strength. Continuous and capacitive SWT had increased muscle strength significantly. We found no clinical significance of all outcomes except pain and functional improvement in pulsed SWT with low dose. There was no difference in adverse events. None of the participants experienced any serious adverse events. Conclusion: Low dose pulsed SWT provided a short-term clinical benefit for pain relief and functional improvement. Pulsed SWD with low and high dose had effects on pain and function. There seems to be a placebo effect. We found significant effects on pain and function in capacitive SWT. Despite some positive findings, this analysis lacked data on how effectiveness is affected by mode, dosage, and application method of SWT. Further well-designed clinical studies are required in order to confirm the effectiveness of SWT.

• Proceedings of the Optical Society of Korea Conference
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• 2006.02a
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• pp.339-340
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• 2006

• CELLMED
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• v.12 no.1
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• pp.2.1-2.9
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• 2022

The study has been carried out for the comparative analysis of relevant literature in order to highlight the present topic "Clinical study on effect on Virechana karma (therapeutic purgation)". Total no. of 40 cases has been selected from OPD and IPD of Panchakarma department, through proper history taking and clinical examination prior to VirechanaKarma. Only VirechanaKarmaYogya subjects were selected for the VirechanaKarma. Analysis of VirechanKarma on the basis of Vegiki (purgative bouts), Maniki (quantity), Langiki (clinical features) and Aantiki (end product) features were done in this study. In this study a highly significant relief was found in patients i.e. p<0.001 due to Virechana mainly vitiated PittaDosha (the heat energy in the body) and secondary Kaphadosha (mucus) and VataDosha (subtle energy associated with movement) are being expelled out which might have accounted for better relief in VirechanYogya (indicated) individuals (Pitta Pradhan Vyadhi (vitiated pitta), RaktajRoga (hemopoietic diseases), ShodhanYogyaAvastha (detoxification), etc.) in the above group of patients. VirechanaDravyas have properties like Tikshna (hyperfunction), Sukshma(subtle), Ushna (heat), etc. are described in Ayurvedic classics which play a vital role in the mode of action of VirechanaKarma has also been explained under probable mode of action.

• The Korean Journal of Pain
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• v.29 no.3
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• pp.153-157
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• 2016

Tapentadol is a novel oral analgesic with a dual mode of action as an agonist of the ${\mu}$-opioid receptor (MOR), and as a norepinephrine reuptake inhibitor (NRI) all in a single molecule. Immediate release (IR) tapentadol shows its analgesic effect quickly, at around 30 minutes. Its MOR agonistic action produces acute nociceptive pain relief; its role as an NRI brings about chronic neuropathic pain relief. Absorption is rapid, with a mean maximal serum concentration at 1.25-1.5 h after oral intake. It is present primarily in the form of conjugated metabolites after glucuronidation, and excretes rapidly and completely via the kidneys. The most common adverse reactions are nausea, dizziness, vomiting, and somnolence. Constipation is more common in use of the ER formulation. Precautions against concomitant use of central nervous system depressants, including sedatives, hypnotics, tranquilizers, general anesthetics, phenothiazines, other opioids, and alcohol, or use of tapentadol within 14 days of the cessation of monoamine oxidase inhibitors, are advised. The safety and efficacy have not been established for use during pregnancy, labor, and delivery, or for nursing mothers, pediatric patients less than 18 years of age, and cases of severe renal impairment and severe hepatic impairment. The major concerns for tapentadol are abuse, addiction, seeking behavior, withdrawal, and physical dependence. The presumed problem for use of tapentadol is to control the ratio of MOR agonist and NRI. In conclusion, tapentadol produces both nociceptive and neuropathic pain relief, but with worries about abuse and dependence.

• Women's Health Nursing
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• v.9 no.2
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• pp.161-169
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• 2003

The purpose of this study was to identify menstrual symptoms, coping and Relief of Symptoms used by female college students. A convenience sample of 202 students were obtained from two colleges in Seoul. Data were collected through questionnaires from September 10 to December 18, 2001, Three instruments were used in this study, the Menstrual Symptoms Questionnaire by Park K. R(1988) and Menstrual Coping Questionnaire and Relief of Symptoms by Billings & Moos(1981) modified for this study. 1)Part time instructor, Department of Nursing, Pochon CHA University The data were analyzed by descriptive statistics, t-test, ANOVA with the SPSS 10.0 program. The result of this study are as follows. 1. Prevalence rate of dysmenorrhea was 91.6%. 2. The total mean score for menstrual symptoms was 1.89 of a possible total of 5 and mean score for each category was, 2.26 for water retention, 2.11 for negative affect, 2.02 for pain, 1.83 behavioral change, 1.69 for autonomic reactions, and 1.53 for concentration. 3. According to the result of this study, statistical differences were found for age (F=3.76, p=0.01), menstrual fear (t=2.02, p=0.04), dysmenorrhea (t=7.73, p=0.02), and taking medication (t=5.95, p=0.00). 4. The coping mode with the highest scores were 'rest and go to bed (83.7%)', 'regard mensturation as a physiological and temporary phenomenon (68.3%)', 'take a warm shower(66.8%)'. The most frequently used methods to relief of symptoms were 'take pain killers (99.9%)', 'to apply hot water bag on painful parts of the body (96.6%)' and 'rest and go to bed (88.8%)'.

• The KSFM Journal of Fluid Machinery
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• v.4 no.4 s.13
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• pp.16-21
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• 2001

The field tests on the waterhammer were carried out for PalDang intake pumping station of the metropolitan water supply 5th stage project. The pumping station was equipped with the pump control valve as the main surge suppression device and the surge relief valve as auxiliary. However, the pump control valve had not been early controlled in the planned closing mode, and the slamming occurred to the valve which abruptly closed during the large reverse flow. Because the pressure wave caused by the pump failure was superposed on the slam surge, the upsurge increased so extremely that the shaft of the valve was damaged. It was desirable that the surge relief valve was installed in the pumping station or near the pump exit for the delay of response. After reforming the oil dashpot of the pump control valve, the sliming disappeared and the measured pressure was in fairly good agreement with the results of simulation. In case of three pumps for ${\phi}2,600$ pipeline being simultaneously tripped, the pressure head in the pumping station increased to 95.6 m, and the upsurge caused by the emergency stop of four pumps for ${\phi}2,800$ pipeline was 89.6m. We concluded that the pumping station acquired the safety and reliability for the pressure surge.

• Journal of the Korean Institute of Landscape Architecture
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• v.24 no.3
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• pp.29-41
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• 1996

The purposes of this study were to develope some techniques which can be used in the landscape simulation process using PC based computer grahics. As a result, a couple of utilities were programmed in AutoLISP language. The one(DSLINE.LSP) is to digitize 2-dimensional structuer forms in the interactive mode considering error handling, and the other one (IMPOST.LSP) is for superimposing and visualizing the digitized plan data to 3-dimension solids & surfaces referring to topographic elevations of meshes in digital terrain model. By applying utilities to present site, the followings may be described. 1) The utility DSLINE.LSP for digitizing simplified building structure form were proved to be easy to input data of polygons including orthogonal edges by handling user coordinates system and checking invalid intersection and default colsing. 2) IMPOST.LSP utility for superimposing and visualizing tool were proved to be more complicated and speedy in calculating process compared with a practical application of modeling tool before rendering process in landscape simulation of built environment on topographic relief, on specially mesospace level of assessment.