• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.12
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• pp.1869-1878
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• 2001

Experiments are carried out to investigate the effect of pulsations on the flow and heat transfer characteristics of an axisymmetric impinging jet on a flat plate heated by using a gold coated aim. Vertex motion in the impinging jet is visualized using a fog generator, and a thermochromatic liquid crystal (TLC) technique is used to measure the time averaged local temperature distributions on the impingement plate. In addition, the quantitative data for mean velocity and turbulence intensity are obtained employing hot-wire anemometer. Parameters such as pulsating frequency (f = 0, 10 and 20 Hz) and the nozzle-to-palate spacing (H/D = 2, 10) are considered at the jet Reynolds number of 20,000. Consequently, the significant changes of flow structure and local Nusselt number distribution due to pulsations are observed. In the case of H/D = 2, the enhanced heat transfer coefficient exceeding 30 % is observed at the stagnation point. At the high H/D, heat transfer rate increases with pulsation frequency.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.497-501
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• 2000

Flow over a sphere is controlled experimentally at $Re=10^5$ using electro-magnetic actuators. The electro-magnetic actuator developed in this study is composed of the permanent magnet electro-magnet membrane and slot. Eight actuators are placed inside the sphere at equally spaced intervals on a latitudinal plane and the position of the control slot is 76 from the stagnation point. Each actuator generates a periodic blowing and suction through the slot at variable frequencies of $10{\sim}140Hz$ and variable amplitudes by controlling electric signals applied to the electro-magnet. Drag on the sphere measured using a load cell is significantly reduced with control at the forcing frequencies larger than the natural shedding frequency $({\approx}14Hz\;at\;Re=10^5)$, whereas drag is slightly increased at the forcing frequency of 10Hz. It is shown from pressure measurement that the static pressure in the rear surface of the sphere is significantly increased with control, indicating that the separation is delayed due to control. Flow visualizations also show that the detaching shear layer is more attracted to the sphere center with control, the separation bubble size is significantly reduced, and motion inside the bubble is very weak, as compared to the case of uncontrolled flow.

• International Journal of Fluid Machinery and Systems
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• v.7 no.3
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• pp.110-124
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• 2014

Surge phenomena in the zone of reduced speeds in a system of a nine-stage axial flow compressor coupled with ducts were studied analytically by use of a surge transient simulation code. Main results are as follows. (1) Expansion of apparently stable, non-surge working area of the pressure vs. flow field beyond the initial stage-stall line was predicted by the code in the lower speed region. The area proved analytically to be caused by significantly mismatched stage-working conditions, particularly with the front stages deep in the rotating stall branch of the characteristics, as was already known in situ and in steady-state calculations also. (2) Surge frequencies were found to increase for decreasing compressor speeds as far as the particular compressor system was concerned. (3) The tendency was found to be explained by a newly introduced volume-modified reduced surge frequency. It suggests that the surge frequency is related intimately with the process of emptying and filling of air into the delivery volume. (4) The upstream range of movement of the fluid mass having once passed through the compressor in surge was found to reduce toward the lower speeds, which could have caused additionally the increase in surge frequency. (5) The concept of the volume-modified reduced surge frequency was able to explain, though qualitatively at present, the behaviors of the area-pressure ratio parameter for the stall stagnation boundary proposed earlier by the author.

• The Journal of Internal Korean Medicine
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• v.25 no.4
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• pp.34-44
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• 2004

Objective : The purpose of this study is to investigate clinical characteristics with 25 patients who have suffered from headache and were treated. Methods : We classified 25 patients into several groups by IHS classification and evaluated the effects of oriental medical therapy on headache. Results : 1. According to the statistics, instances of migraine were more prevalent than tension headache, especially among women. 2. 28% of patient had entered for treatment within one month of onset. 3. Common associated symptoms included dizziness, nausea, dyspepsia, palpitation and insomnia. 4. In classification by the oriental medical differentiation of symptoms and signs, the rate of stagnation of the humid dam and deficiency of qi, these two types were highest. 5. 56% of patients said they were satisfied with the treatment, reporting half the frequency of headache or better from before treatment. Conclusions : The present results suggest that oriental medical therapy has effects on headache. Further clinical comparative studies on herb-medication versus acupuncture therapy for headache are urged.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.1
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• pp.101-109
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• 2002

Two perforated plates are used to investigate local heat/mass transfer characteristics in an impingement/effusion cooling system. A naphthalene sublimation method is conducted to determine the local heat/mass transfer coefficients on the upward facing surface of the effusion plate. Two plates are placed in parallel position with gap distances of 1, 2, 4 and 6 times of effusion hole diameter. The effects of hole arrangements of the plates are studied fur staggered, square, and hexagonal arrays. The experiments are conducted at Reynolds number of 10,000 based on the effusion hole diameter. The results show that the smaller hole size in the staggered array has the higher transfer coefficients on the stagnation region due to the formation of higher momentum flows through the impingement holes. In the square array, heat/mass transfer on the target plate is more uniform as the number of impingement holes increases. High and uniform heat/mass transfer coefficients are obtained for the hexagonal array.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.9 no.2
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• pp.9-18
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• 1991

A diagram has been annexed to the spot inspection record of the traffic accident were drawn up with measuring-tape heretofor. However, conventional reduction method have been usually contained the various problems according to the social development. To solve these problems, it was performed that photogrammetric method are measured 3-D coordinate of needed points and precised plotting of traffic accident spot investigation. Also, they have produced some good effects on speedy spot investigation and settlement of traffic stagnation. Because semi-metric camera and MR2 system are utilize for low cost, simple operation and almost unnecessary for control point surveying, these fittings being at the close-range photogrammetry will be extremely powerful over versatile fields like traffic accident in police.

• Journal of Korean Society for Quality Management
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• v.41 no.1
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• pp.1-14
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• 2013

Purpose: The purpose of this research was to investigate the spread pattern of Korean legal certification systems and their impact on industry performance. Methods: It first analyzes the life cycle of legal certification systems and classifies them into four categories based on the spread patterns in a chronological view. A survey study is then conducted to find out the impact of legal certification systems on financial performance. Both the legal mandatory certification systems and the legal voluntary certification systems are included in the survey. Results: Four spread patterns of legal certification systems are sustainable growth, stagnation after growth, decrease after growth, and repetition of growth and declination. 56% of 293 certified corporations responded positively about the financial impact of their certification systems. Conclusion: The policy makers can utilize the results of this study in designing additional certification systems as well as promoting the current legal certification systems.

• Journal of Korean Society of Rural Planning
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• v.23 no.3
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• pp.97-105
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• 2017

The interest and participation of the rural experience is increasing as an alternative for the problems such as the decrease of the agricultural income facing the agriculture and the rural area, the decrease of the population, and the regional stagnation. The rural experience has recently been transformed into a software dimension such as programs and participation activities in the past. In addition, public awareness also positively evaluates agriculture and rural communities as the basis for supporting society and recognition of multiple functions. Furthermore, the intention of the citizen to the earnest village is increasing. The purpose of this study is to analyze the effect of rural experience and customer satisfaction of urban residents on the recognition of return to farm and rural areas. As a result of the analysis, it was found that the characteristics of rural experience had a positive effect on the farming villages by the program, the experience field and the host, and the customer satisfaction had a positive effect on the farming villages. Therefore, it is considered that a systematic approach to the rural experience is needed in the future because the experience of the rural people in the city has a positive effect on the earliest villages.

• The Journal of Internal Korean Medicine
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• v.28 no.3
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• pp.502-509
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• 2007

Objectives : Folium perillae (FP) can relieve superficial pathogenic factors to dissipate cold and promote the circulation of qi and regulate the function of the stomach and is often used for interior qi-stagnation. We hypothesized that FP could rescue cerebral ischemia in rats. Methods : The present study was carried out to investigate the effects of FP on cerebral ischemia in terms of regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP) in rats. Finally, lactate dehydrogenase (LDH) release was investigated, too. Results : In this study, treatment with FP elevated rCBF and MABP levels in dose-dependent manner. Pre-treatment with indomethacin, an inhibitor of cyclooxygenase, inhibited rCBF increase induced by FP effectively. However, FP did not affect stability during cerebral reperfusion. Finally, FP significantly inhibited LD H activity in vitro Conclusions : These results suggest that FP is useful to treat patient with diseases related to cerebral ischemia, because FP can increase rCBF and MABP.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.3
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• pp.740-747
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• 2006

This study was undertaken to clinically inspect the accuracy of DSOM-diagnosis System of Oriental Medicine, which were used for the object diagnosis of oriental medicine in the dept. of oriental OB&GY, oriental medical hospital of Dong-Eui University- about uterus myoma patients. We analyzed the prescription and consequence of diagnosis about 16 patients -who had uterus myoma, were treated more than one month, were improved in myoma size, dysmenorrhea, menorrhagia- in the oriental medical hospital of Dong-Eui University from January to December 2004. The calculation consequence of disease mechanism was as follows. The stagnation of Ki(氣滯), liver(肝), heart.(心) was 10 patients 71.4%, some deficiency(虛證), wet syndrome(濕), cold syndrome(寒) was 9 patients 64.3%, blood stasis(血奈) was 8 patients 57.1%. The agreement of consequence about DSOM and diagnosis was 13 patients, 92.9%.