• Journal of Mechanical Science and Technology
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• v.18 no.8
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• pp.1338-1348
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• 2004

A simplified method that models the deflagration process occurring in closed or vented vessels is described. When combustion occurs within the spherical or cylindrical vessels, the flame moves spherically or segmentally to the vessel periphery. The volume and area of each element along the propagating flame front are calculated by using simple geometrical rules. For instabilities and turbulence resulting in enhanced burning rates, a simple analysis results in reasonable agreement with the experimental pressure transients when two burning rates (a laminar burning rate prior to the onset of instability and an enhanced burning rate) were used. Pressure reduction caused by a vent opening at predetermined pressure was modeled. Parameters examined in the modeling include ignition location, mixture concentration, vented area, and vent opening pressure. It was found that venting was effective in reducing the peak pressure experienced in vessels. The model can be expected to estimate reasonable peak pressures and flame front distances by modeling the enhanced burning rates, that is, turbulent enhancement factor.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.439-444
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• 2005

Steady state simulation and dynamic simulation were performed to analyze the operational characteristics of a multi-type refrigeration system, Fully distributed model was adopted to simulate the steady state and transient responses of the system. The main aim was to see the effect of one indoor unit on the other unit. Numerical simulations were carried out for various operation conditions of an indoor unit - secondary fluid inlet temperature, mass flow rate and expansion valve opening. The results showed that the inlet temperature and mass flow rate of the secondary fluid of one indoor unit had minor effect on the operation of the other unit. However, the opening of the expansion valve had significant effect on the performance of the other unit.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.3
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• pp.235-240
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• 2008

The large size electromagnetic flowmeter was tested to investigate the variation of its error characteristics in the range of low velocity under 0.6 m/s using flowmeter calibration system. For the two case of valve opening rate 100 % and 50 %, these tests were undertaken three times each for twelve velocity condition from $0.05\;^m/s\;to\;0.6\;^m/s$ with increment of $0.05\;^m/s$. It is shown that error characteristic of electromagnetic flowmeter was stabilized within ${\pm}0.4%$ of rate both higher than $0.25^m/s$ of velocity condition and 50 % of valve opening position. But, measurement deviation of flowmeter for ${\Phi}400mm\;and\;{\Phi}600mm$ was out of expected deviation range. It is necessary to correction with calibration. In conclusion, error characteristic of electromagnetic flowmeter wasn't changed proportion to its size.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.9
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• pp.699-703
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• 2012

The performance of the typical VAV dampers; blade type, venturi type and blade-orifice type, for the circular duct, is obtained by measuring the volume flow rate as a function of the opening degree. The performance features are discussed by comparing the volume flow rate of each damper. It is shown that the blade-orifice type damper, recently developed, is excellent in its linearity of the performance and that it is worse than the blade type but much better than the venturi type in its flow resistance.

• Korean Journal of Adult Nursing
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• v.24 no.2
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• pp.130-138
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• 2012

Purpose: The purpose of this study was to verify the effects of gum chewing temporalis muscle exercise on masticatory discomforts after craniotomy. Methods: Data collection was performed from July 10 to October 24, 2008. Forty participants who were treated with elective craniotomy were enrolled in this study. Twenty participants in the exercise group were given a gum chewing exercise protocol for five days and twenty participants in the control group received usual postoperative care only. All the participants were examined on the first, third and fifth postoperative day regarding the masticatory pain score, mouth opening range, and satisfaction with mastication. Collected data were analyzed using t-test, $x^2$-test and repeated measures ANOVA. Result: Masticatory pain of experimental group was significantly lower than the control group ($p$ <.001). Mouth opening range and satisfaction with mastication of experimental group were significantly improved in experimental group compared with the control group ($p$ <.001). Conclusion: The gum chewing temporalis muscle exercise after craniotomy is a useful intervention to reduce masticatory pain and to improve mouth opening range, recovery rate of mouth opening range and satisfaction with mastication.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.3
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• pp.528-537
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• 1995

Natural convective flow and heat transfer characteristics in a partially opened enclosure fitted with a horizontal divider are investigated numerically. The enclosure is composed of a lower hot and a upper cold horizontal walls and adiabatic vertical walls. A divider is attached perpendicularly to the vertical insulated wall. The governing equations are solved by using the finite element method with Galerkin method. The computations have been carried out by varying the length of divider, the opening size, and the Rayleigh number based on the temperature difference between two horizontal walls and the enclosure height for air(Pr=0.71). As result, when the opening size is fixed, the intensity of the secondary flow is weaken as the length of divider increases. The maximum heat transfer rate over the upper cold wall occurs at a position bounded on the opening. However, when the length of divider is increased considerably, its maximum occurs at the right wall. The stability and frequency of oscillation are affected by the Rayleigh number and length of divider. The Nusselt number is increased with the increase of the opening size and the increase of Rayleigh number.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.1
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• pp.96-102
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• 1990

Cracks found in pressure vessels have been reported to be mostly semi-elliptic surface cracks. The fatigue crack growth behaviour of the surface cracks on pressure vessel materials, SPV 50Q and API 5A-K55, was studied with the consideration of the crack opening character. To determine the crack opening loads for the surface cracks, the displacement/strain were measured at three positions; the center and the side of the surface crack, the back face of the specimen using CMOD gauge and strain gauges. The experimental results showed that the crack opening load levels measured at the side of the surface crack were generally a little higher than those measured at the back face. As for the crack growth rates at the different parts of the surface crack, the experiments also showed that, if .DELTA.K$_{eff}$ is used, the exponent n of the Paris' law obtained were the same for the rear and the side parts of the surface cracks.

• Journal of the Korea Convergence Society
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• v.11 no.2
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• pp.155-160
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• 2020

In this study, the pleasant driving environment of the driver and passenger in the summer was investigated through the internal flow analysis of air due to the opening and closing of the car windows. The conditions on the entrance of the air conditioner with the opening and closing status of vehicle window were applied to the flow analysis by taking into consideration the actual driving environment. The automotive air conditioning outlet, the seat and the inside of car were modeled. As the air flow inside the car was analyzed, the air flow configuration and the temperature distribution were examined. In this analysis, the results were taken in consideration of only the effects of internal air and the opening and closing of window, assuming the interior of the vehicle as insulation. The analysis of each condition shows that these models maintain a pleasant environment. It is seen that this analysis result on the internal flow analysis according to the opening and closing of vehicle window can be applied by converging with the field of design.

• The Korean Society of Law and Medicine
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• v.15 no.2
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• pp.345-366
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• 2014

Because the health care or medical sector has such characteristics as publicity, professionality, and exclusivity, it cannot be left to the free market system. As a consequence, the state has restricted the establishment of medical institutions in order to protect the life and health of people. Also, the medical law has regulated to permit the establishment of medical institutions by only medical personnel and a few corporate bodies and to ban the establishment of medical institutions under disguised ownership as well as double opening of medical institutions by medical personnel. Nevertheless, there are still many cases that non-medical personnel have dominantly established medical institutions under disguised ownership of other medical personnel or nonprofit corporation. Because they are willing to recover their investment costs as soon as possible, these illegally established medical institutions are likely to make patients undergo unnecessary tests or to perform the excessive treatments and, as a result, are likely to cause infringement on the health and lives of the people. In addition, even if the misconduct is uncovered, the rate at which the costs already paid is very low and, as a result, the damages are straightly connected to the people's loss. On the other hand, there are also increasing number of cases that medical personnel or nonprofit corporations are establishing medical institutions against the medical law regulations. The examples of this illegality are also the double opening of medical institutions and the establishment of medical institutions under disguised ownership by medical personnel or nonprofit corporations. And the damages in these cases may not differ from those in the above cases. In this study, regarding medical law regulations restricting opening a medical institution, I will review the intent of those regulations, the type of violations and criminal punishments, and the possibility of recovery from unlawful profit by the National Health Insurance Act. And then, I would like to find a way for rational improvement of each.

• The Journal of the Korean dental association
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• v.57 no.9
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• pp.514-522
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• 2019

In accordance with Article 33(8) of the Korean Medical Law, it is stated that a medical person cannot open or operate a medical institution by borrowing the name of another medical person. However, the publicity of medical care is threatened by the recent illegal network dental clinics. The purpose of this study is to investigate the actual condition of illegal network dentistry and to analyze the cases and to find out the reason why the prohibition of double opening & operating of medical institution. As a result, the illegal network dental clinics treated less health care insurance treatment such as dental caries and periodontal treatment than general dental hospitals. In contrast, the rate of implementation of illegal network dentistry was high in endodontics treatment and extraction, which could lead to uninsured treatments such as crowns and implants. As a result of Supreme Court precedent analysis, it is concluded that illegal act is not only the opening of a medical institution by borrowing the name of other medical personnel, but also the duplicated operation which has the authority to make decision about management matters of medical institutions. The results of the patient's case survey also showed that excessive dental treatment due to such as dental staff incentive system. In conclusion, the illegal network dental clinics not only threatens the oral health of the public, but also causes leakage of health insurance premiums. In other words, the ban on opening and operating the multiple medical institution should be strictly applied as a strong protection device for protecting the patient in dental case.