• Journal of the Institute of Convergence Signal Processing
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• v.14 no.3
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• pp.205-211
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• 2013

Recently, the needs of system performances such as working speed and processing accuracy in machine tools have been increased. Especially, the working speed increment generates harmful heat at both moving part of the machine tools and handicrafts. The heat is a main drawback to progress accuracy of the processing. Hence, a oil cooler to control temperature is inevitable for the machine tools. In general, two representative control schemes, hot-gas bypass and variable speed control of a compressor, have been adopted in the oil cooler system. This paper deals with design and implementation method of fuzzy controller for obtaining precise temperature characteristic of HB oil cooler system in machine tools. The opening angle of an electronic expansion valve are controlled to keep reference value and room temperature of temperature at oil outlet. Especially, the fuzzy controller is added to suppress temperature fluctuation under abrupt disturbances. Through some experiments, the suggested method can control the target temperature within steady state error of ${\pm}0.22^{\circ}C$.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.5
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• pp.459-469
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• 2017

A real scale leakage test facility was developed to study the leak signal characteristics of water supply pipelines, and then leak tests were carried out. The facility was designed to overcome the limited experimental circumstances of domestic water supply pipeline experimental facilities. The length of the pipeline, which was installed as a straight line, is 280m. Six pipes were installed on a 70m interval with different pipe material and diameters that are DCIP(D200, D150, D100, D80), PE(D75) and PVC(D75).The intensity of the leakage is adjusted by changing the size of the leak hole and the opening rate of ball valve. Various pressure conditions were simulated using a pressure reducing valve.To minimize external noise sources which, deteriorate the quality of measured leak signal, the facility was built at a quiet area, where traffic and water consumption by customers is relatively rare. In addition, the usage of electric equipment was minimized to block out noise and the facility was operated using manual mode. From the experimental results of measured leakage signal at the facility, it was found that the signal intensity weakened and the signal of high frequency band attenuated as the distance from the water leakage point increased.

• Korean Journal of Acupuncture
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• v.20 no.1
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• pp.21-30
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• 2003

Objectives : The pain was induced on upper and lower incisor of the rat based on the theory of 'connections of upper incisor pain with stomach meridian and lower incisor pain with large intestine meridian'. Such acupoints as LI4 and ST36 were used for alleviation of upper and lower incisor pain. Methods : The digastric myogram (dEMG) was utilized for the pain measurement. Results : The ST36 acupuncture after induction of upper incisor pain was gradually decreased or increased the dEMG. The LI4 acupuncture after induction of upper incisor pain was gradually decreased the dEMG. The ST36+LI4 acupuncture after induction of upper incisor pain was gradually decreased the dEMG. We knew this thing which the ST36+LI4 acupuncture decreased the dEMG most greatly and kept long compared to ST36 acupuncture, LI4 acupuncture. Conclusions : Acupuncture treatment at the loci of not only ST36 acupuncture but LI4 acupuncture were relieved the upper incisor pain. It was well suitable to the theory 'connections of upper incisor pain with stomach meridian' that ST36 acupuncture decreased the upper incisor pain. But there was not to decrease the dEMG for the ST36 acupuncture. We are considered as tracing study continuously about ST36 acupuncture. It was not suitable to the theory 'connections of upper incisor pain with stomach meridian' that LI4 acupuncture decreased the upper incisor pain. These results was considered as the function by the characteristic of the LI4 acupoint.

• Aerospace Engineering and Technology
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• v.10 no.1
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• pp.79-88
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• 2011

A fill-drain valve is operated by provided control gas at the ground for liquid propellant feeding system of space launch vehicle, which fills or drains on-board propellant tanks with a cryogenic oxidizer. We have analyzed and modified the data of fill-drain valve designed by Yuzhnoye. The simulation model of fill-drain valve is designed by using the AMESim code to predict and evaluate the dynamic characteristics and pneumatic behavior of valve. In this study, we performed a dynamic characteristic simulation on design parameter. And we could predict opening/closing time and pressures, operating performances on design parameters. This study will serve as one of reference guides to enhance the developmental efficiency of fill-drain valves with the various operating requirements, which shall be used in the Koreanized Space Launch Vehicle.

• Special Issue of the Society of Naval Architects of Korea
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• 2007.09a
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• pp.118-127
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• 2007

SAW(Submerged Arc Welding) process is generally applied to a wide range of welding area in the fabrication of steel structure. This process has a good characteristic properties such as the high quality of welds and the high deposition rates, but in case of welding on a thick steel plate, it also has higher cold crack susceptibility than that of a thin steel plate. The purpose of this research is to find the main factor of crack generation and clarify the countermeasure for crack prevention, and then establish the optimum welding condition in a heavy thick steel plate. The results of this study are as follows, 1. The cause of crack generation is found the diffusible hydrogen penetrated into weld metal by decomposition of the remained moisture in SAW flux during welding. 2. For the removal of diffusible hydrogen, the raw materials of SAW flux are to be dehydrated at the high temperature in the initial manufacturing stage. 3. Mechanical properties of weld metal welded with the dehydrated SAW flux were evaluated very excellent, furthermore the weld metal has been proved to have low diffusible hydrogen content with 3.1ml /100g. 4. The weldability and quality welded with thick steel plates were improved by establishing the new optimum welding condition.

• Proceedings of the KWS Conference
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• 2001.05a
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• pp.224-227
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• 2001

In this study, CT specimens were prepared hem ASTM SA516 which was used for pressure vessel plates for room and low temperature service. And we got the following characteristics from fatigue crack growth test carried out in the environment of room and low temperature at $25^{\circ}C$, -3$0^{\circ}C$, -6$0^{\circ}C$, -8$0^{\circ}C$, -l$0^{\circ}C$ and -l2$0^{\circ}C$ and in the range of stress ratio of 0.1, 0.3 by means of opening mode displacement. At the constant stress ratio, the threshold stress intensity factor range $\Delta K_{th}$ in the early stage of fatigue crack growth ( Region I ) and stress intensity factor range $\Delta$K in the stable of fatigue crack growth ( Region II) was increased in proportion to descend temperature. It assumed that the fatigue resistance characteristics and fracture strength at low temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region. The straight line slope relation of logarithm da/dN - $\Delta$K in Region II, that is, the fatigue crack growth exponent m increased with descending temperature at the constant stress ratio. It assumed that the fatigue crack growth rate da/dN is rapid in proportion to descend temperature in Region H and the cryogenic-brittleness greatly affect a material with decreasing temperature.

• Journal of the Korean Society of Costume
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• v.59 no.8
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• pp.82-96
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• 2009

The purpose of this study is to present the basic approach of producing the luxury fashion brands containing of the Korean traditional traits on the basis of traditional transformation with the modern concept, taking the 'Vivienne Tam' 2000's collections. This study has focused on its transformation of the traditional one of China, and made this as the subject of investigation. It's design characteristic could be defined as "modern interpretations of China chic", and it would be divided into two groups. The ingenious mixture of Chinese tradition into the modern chic could be concluded like these. The external characteristics is categorized in the three ways (1) the aesthetic application of the Chinese traditional patterns(dragon, water waves, peony, Japanese apricot flower, bamboo, bats, Chinese characters etc.), (2)the modern application of Chinese traditional costume details(front opening of Chipao, mandarin collar and knot buttons) and (3)the modernization of Chinese traditional technique(knotting, embroidery, beading and paper cutting). To deal with the internal characteristics, (1)the aesthetic mixture of East and West, (2)the formative expressions of the traditional view on the universe and religion are remarkable. The Chinese embodiment and the view of the universe and religion was integrated into the patterns of dragon, water waves, clouds, fire, woods, and metals. In order to afford the creative designer capable of encompassing the East and West, the teaching about the Korean tradition along with the technical and practical aspect of fashion is most important, while encouraging the professional designer to make a sophisticated ones which are attributed to the Korean tradition, and thereby come to be attractive to the world customer. The study about the Korean costumes, traditional colors, the symbolic meaning of the traditional patterns, cuttings, compositions, extending to the various kinds of myths, songs, paintings and crafts are essential for the Korean designer brand to be the global luxury brands.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.5
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• pp.60-71
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• 2007

The startup characteristic of liquid propellant rocket engine should be focused on the stable ignition of combustion chamber and gas generator. Also, to lessen the propellants consumption during this period which doesn't contribute to the flight thrust, the engine has to be transferred to the nominal mode quickly. Because of the risk of test, it is impossible to develop all the startup cyclogram or the specifications of engine by test, so the precedent numerical approach is quite necessary. In this study we developed a mathematical model for the startup phenomena in a liquid rocket engine driven by gas generator-turbopump system based on the commercial 1-D flow system analysis program, Flowmaster. Using this program we proposed a methodology to obtain the specifications of turbine starter and the opening time of shutoff valves for the stable startup of the engine. To verify this methodology we qualitatively compared the analysis results to the typical startup curve of the published engine, then found it is quite well matched.

• Journal of Korea Port Economic Association
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• v.25 no.1
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• pp.271-292
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• 2009

Opening and regional economic integration are characteristic of global economic trends that have been made since the 1990s. Accordingly, all economic blocs of the world are largely reorganized into three poles, European Economic Bloc, American Economic Bloc and Northeast Asian Economic Block which are respectively led by EU, the United States and the rapidly emerging economic power, China. Considering this direction of global economy, the current status of Northeast Asia, China's unprecedentedly enormous port development project and Japan's introduction of an epoch-making port policy towards the restoration of its port competitiveness, Korea is urgently need to take its own initiatives and positive actions that can cope with the above situations. The purpose of this study is to propose ways of strategic cooperation for Korea-Japan joint development. For the purpose, this researcher provides the concept and preconditions of hub-port, investigates hub-port development strategies of rival companies in Northeast Asia and discusses the potential of the development of the Korea-Japan Strait Economic Zone which is located between Busan port and Japan's Honshu(Simonoseki port) and Kyushu(Kitakyushu port).

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.6
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• pp.803-811
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• 2012

Oriental Medicine always attach great importance to the damp diseases. Dampness is related with many organs and many clinical diseases. The cause and the location of the damp disease, nature of the symptoms, combination with other pathogenic factors are very diverse. This article analyzed the concept, cause of disease, pathogenesis, characteristic of symptoms, treatment method and prescriptions of Epidemic Warm Diseases of dampness syndrome and cases of dampness-heat diseases based on the theories of Epidemic Warm Diseases and found that theories of Epidemic Warm Diseases have very wide area of application. Dampness is classified into cold-dampness and dampness-heat by combination of heat or cold. The dampness syndrome is related with organs such as lung, spleen, kidney, triple energizers and bladder, and affects liver and heart. The basic treatment methods are dispelling dampness turbidity and diffusing qi movement. The detail treatment methods are spreading lung qi with lightness and resolving dampness and excreting turbidity in upper energizer, opening and dipping down with pungent-bitter and diffusing qi movement and strengthening the spleen and stomach in the middle energizer, draining dampness with bland in the lower energizer. Warming Yang is the main method of treatment for cold-dampness and clearing heat is for dampness-heat with the assistant methods such as resolving dampness and promoting the flow of qi. 5. Acute fever, virus diseases, epidemic diseases among modern diseases are much related with the dampness-heat syndrome.