• 한국해양공학회지
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• 제11권3호
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• pp.56-68
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• 1997

This work was intended to study the effect of a partial pressure ratio and a total pressure of reactive gases on the properties of TiC$_{x}$N$_{1-x}$ . coated layer. In this regard, various TiC$_{x}$N$_{1-x}$ coatings were synthesized with C2112 and N2 Mixture gas of different compositions by Arc Ion Plating process which has been highlighted for an industrial purpose. It was revealed from colors and X-ray diffraction patterns that the concentration of carbon of a TiC$_{x}$N$_{1-x}$ coating increases with a partial pressure ratio (PC$_{2}$H$_{2}$/PN$_{2}$) as well as a total pressure Of $C_{2}$H$_{2}$ and N$_{2}$ mixture gas. Accordingly, the hardness of TiC$_{x}$N$_{1-x}$ coated layer increased but the adhesion to the substrate of SKH 51 was degraded. On the other hand, the deposition rate was independent of a partial pressure ratio and a total pressure of mixture gas. It was found that a uniform gas distribution is critical for an industrial application since the composition of a coating depends strongly on the location of a substrate inside of the furnace. As a result of milling tests with different TiC$_{x}$N$_{1-x}$ coated end mills, the one which has a low carbon concentration was better than others studied in this work.d in this work.

• 한국군사과학기술학회지
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• 제4권2호
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• pp.215-224
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• 2001

An experimental investigation was conducted on the interaction of vortices over a delta wing with the leading edge extension for three angles of attack($16^{\circ},\; 24^{\circ} \;and\; 28^{\circ}$) at Reynolds number of $1.76{\times}10^6.$ The experimental data included total pressure contours and velocity vectors using 5-hole probe measurements. Constant total pressure coefficient contours show the LEX vortex moves downward and outboard, while the wing vortex exhibited an inboard and upward migration. At near the trailing edge, these vortices reveal a direct interaction between the wing and LEX vortex, featuring a coiling of vortex cores about each other. The combined effect of the interaction of these two vortices and proximity to the wing surface results in the increase of the suction peak. This is in contrast to the result obtained on the delta wing alone configuration, where the effect of the vortex breakdown was manifested. The interaction of the wing and LEX vortices is more pronounced at higher AOA.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.688-692
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• 2001

Three-dimensional experimental analyses were conducted in the pulverizer simplified isothermal model. The experimental model was constructed on a 1/3.5 scale of 500MW pulverized coal boiler. The purpose of this study is to investigate the characteristics of coal particle separator and the pressure loss in the pulverizer models with dynamic classifier. Without regards a shape of separator top, the results showed that the increase of dynamic classifier rpm was induced in finer coal particle. But the capacity of total mass per minute was reduced. Also, the increase of dynamic classifier rpm had no effect on total pressure loss, but an increase of inlet velocity was induced that the rise of total pressure loss in the pulverizer models with dynamic classifier.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2002년도 춘계 학술대회논문집
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• pp.29-34
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• 2002

TIn this study, the counter-jet flows which designed for improvement of aerodynamic performance of the blunt body vehicle have been analyzed. The variations of the drag force and jet penetration depth due to changes in the stagnation properties of counter jet new such as total pressure, mach number, and total temperature. The counter jet flow, which is injected toward incoming supersonic freestream at stagnation region of blunt cone-cylinder vehicle, have been studied by using upwind flux difference splitting navier-stokes method. The changes in the stagnation pressure and Mach number resulted in large effects on the wall pressure and drag force, on the other hand tile total temperature changes did not.

• Journal of Acupuncture Research
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• 제25권6호
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• pp.13-22
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• 2008

Objectives : Aim of this study was to investigate the antihypertensive effect of Gyeok-Pal Sang-Saeng-Yeok-Chim acupuncture treatment in hypertensive patients. Methods : The research subjects were a total of 26 hypertension patients. Eligible participants had systolic blood pressure ${\geq}140mmHg$ or diastolic blood pressure ${\geq}90mmHg$ with antihypertensive drug. Both the experimental and control group were divided into 13 participants respectively with homogeneous consideration. The experimental group had acupuncture treatment, Gyeok-Pal Sang-Saeng-Yeok-Chim, whereas the control group didn't have any treatment. Blood pressure was measured before and after acupuncture treatment for a total of 12 times. Results : After 4 weeks of treatment we could identify a decrease in both systolic and diastolic blood pressure in acupuncture, Gyeok-Pal Sang-Saeng-Yeok-Chim, treated group compared to that of control group. The given results by measuring time on blood pressure were as follows: Significant decrease in systolic blood pressure from the $1^{st}$ to $12^{th}$ day of visit(P<0.05) while diastolic blood pressure did not show significant decrease. Conclusions : The results suggest that Gyeok-Pal Sang-Saeng-Yeok-Chim acupuncture treatment is effective in decreasing blood pressure but with statistical restriction compared to that of control group.

• KIEAE Journal
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• 제12권6호
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• pp.23-28
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• 2012

Pressure distribution in the water supply system of an apartment complex consisting of 12 buildings and 635 units in total have been investigated numerically. The complex incorporates two zone booster pump system, and around a half of units have pressure reducing valves (PRVs) in them. Calculated hydrostatic pressure without the water flow were compared with their designed and measured counterparts, and they agreed quite well with each other. Then, the pressure and volumetric water flow rate at all units were analyzed, indicating that there are noticeable differences in pressure and flow rate in one unit to another, although the aforementioned minimization technologies of pressure deviation were employed. In order to further reduce the difference in the water flow rate, it is suggested that all the units in the complex have PRVs installed in their water supply system. The effect of setting pressure of the PRVs on the non-uniformity of the flow in each unit and on the reduction of total water supply for the apartment complex have been studied. With the same PRV setting pressure of 3.952 bar (or the gauge pressure of $3.0kg_f/cm^2$), it has been estimated that the suggested system improves the non-uniformity (the coefficient of variation) of the flow rate of apartment complex over the current system, from 8.02% to 6.66%, and reduces the total water supply, from $0.02804m^3/s$ to $0.02766m^3/s$.

• 한국표면공학회지
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• 제26권1호
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• pp.3-9
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• 1993

Chemical vapor deposited tungsten films were formed in a cold wall reactor at pressures higher (10~120torr) than those conventionally employed (<1torr). SiH4, in addition to H2, was used as the reduction gas. The effects of pressure and reaction temperature on the deposition rate and morphology of the films were ex-amined under the above conditions. No encroachment or silicon consumption was observed in the tungsten de-posited specimens. A high deposition rate of tungsten and a good step coverage of the deposited films were ob-tained at 40~80 torr and at a temperature range of $360~380^{\circ}C$. The surface roughness and the resistivity of the deposited film increased with pressure. The deposition rate of tungsten increased with the total pressure in the reaction chamber when the pressure was below 40 torr, whereas it decreased when the total pressure ex-ceedeed 40 torr. The deposition rate also showed a maximum value at $360^{\circ}C$ regardless of the gas pressure in the chamber. The results suggest that the deposition mechanism varies with pressure and temperature, the surface reac-tion determines the overall reaction rate and (2) at higher pressures(>40 torr) or temperatures(>36$0^{\circ}C$), the rate is controlled by the dtransportation rate of reactive gas molecules. It was shown from XRD analysis that WSi2 and metastable $\beta$-W were also formed in addition to W by reactions between WF6 and SiH4.

• 성인간호학회지
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• 제19권3호
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• pp.339-352
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• 2007

Purpose: The purpose of this study was to investigate the effect of weight control program on body composition(body mass index and waist-hip ratio), blood pressure, serum lipids(total cholesterol, triglyceride, high density lipoprotein and low density lipoprotein) and self-regulation behavior in obese college women. Methods: Forty seven obese subjects were divided into experimental(22) and control(25) groups. The weight control program lasting 12 weeks consisted of a traffic-light diet, jumping-rope exercises, and behavior modification methods with e-mail counseling. The data were collected from 29 March to 17 September of 2004. The variables were assessed before and after intervention for 12 weeks in two groups. Then, those were repeated after a 12 week suspension of intervention in the experimental group. The data were analysed by the SPSS computer program. Results: BMI, HDL, LDL and self-regulation behavior levels showed significant differences between the experimental and control groups. While there were no significant differences in waist-hip ratio, blood pressure, total cholesterol and triglyceride. Conclusion: The weight control program had a positive effect on obese college women, and can be used to control obesity.

• 한국산업융합학회 논문집
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• 제25권4_2호
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• pp.565-572
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• 2022

The white plume from the cooling tower can be generated by mixing between discharging hot and humid air and cold air outside. This causes various problems such as icing, traffic disturbances, and fire factors in the vicinity, moreover it can also damage the image of a company. Various methods can be used to prevent white plume, one of them is to install a heat exchanger at the outlet of the cooling tower so that the heat exchanger transfers as much heat as possible to lower the temperature. Therefore the air flow path in the cooling tower should be optimized. Installation of the filler can be used to make the air flow better, thus we investigate the effect of filler on the air flow using CFD method. The pressure and velocity profile in the cooling tower could be acquired by the calculations. The filler made the velocity of the air entering the heat exchanger uniform this was because high flow resistance of the filler suppresses the generation of eddy in the cooling tower. But the total air pressure drop increased about 2 times with filler because the pressure drop by the filler accounted for about 60% of the total pressure drop.

• Journal of Acupuncture Research
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• 제23권4호
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• pp.49-60
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• 2006

Objectives : The aim of the study was to investigate the antihypertensive effect of Gyeok pal sang saeng Yeok chim Acupuncture in hypertensive patients. Methods : We measured the blood pressure of the patients who were admitted in the Oriental Medical Clinic of Brother from 13th February 2006 to 13th May 2006. We included the patients only in case of the systolic blood pressure was over 120mmHg or diastolic blood pressure was over 80mmHg, thirty patients were treated by Gyeok pal sang saeng Yeok chim Acupuncture. In order to evaluate the effect of the Gyeok pal sang saeng Yeok chim Acupuncture, the blood pressure and pulse rate were measured before and after Acupuncture procedure total 10 times. Results : There were significant decrease in the systolic blood pressure and significant decrease in the diastolic blood pressure treated by Gyeok pal sang saeng Yeok chim Acupuncture 10 times but pulse rate was not significantly decreased. The effect of Gyeok pal sang saeng Yeok chim Acupuncture by measurement time on blood pressure were follows: In a systolic blood pressure and diastolic blood pressure was gradually deceased significantly from 1st to 10th but pulse rate was not significantly decreased. Conclusion : These results suggest that Gyeok pal sang saeng Yeok chim Acupuncture is effective in decreasing the systolic and diastolic blood pressure.