• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.188-188
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• 2004

Modal testing and analysis is a primary tool for obtaining reliable models to represent the dynamics of structures. When a structure is tested in order to collect measured data in modal testing, we usually use attached accelerometers to pick up the response data. Change in modal parameters due to the mass of transducers in modal testing is a well-known problem. The disadvantages are the shift of measured modal frequencies and the change of modal shapes, which can cause inaccurate results in further analysis. Modal analysis methods in frequency domain are based on a set of measured frequency response functions(FRF).(omitted)

• Journal of Plant Biology
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• v.36 no.3
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• pp.203-210
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• 1993

In order to investigate the effects of plant hormones on the quantitative changes in mRNA of maize (Zea mays L.) rbcL, we used GA3, IAA, ABA and BAP. GA3 at the concentration of 10-4M resulted in decrease in rbcL gene transcript to 62%. IAA decreased the amount of rbcL transcript to about 70% at all the hormone concentrations tested. ABA did not cause a noticeable change in the amount of rbcL transcript, but BAP increased the amount of rbcL transcript to 153% at 10-8M and 123% at 10-5M, respectively. Thus, it appears that BAP is related to the increase in the amount of rbcL transcript by light.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.3
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• pp.11-17
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• 2012

In this study, an experiment with large-scale model was performed according to raising embankment in order to investigate the cause of collapse by a change in water level of reservoir. Also, the settlement and pore water pressure by high water level and a rapid drawdown were compared and analyzed. After raising embankment for inclined core, there was no infiltration by leakage. For the vertical core, the pore water pressure showed a largely change by faster infiltration of pore water than in the inclined core. In a rapid drawdown, inclined core was remained stable but vertical core showed a largely change in pore water pressure. A settlement after a raising embankment showed a larger measure of settlement than before the raising embankment. The leakage quantity before a raising embankment and an inclined extension showed no leakage. Leakage in vertical extension was measured 160 $l$. From the result, a instrument system that can accurately estimate a change of pore water pressure shall be established for a rational maintenance and stabilization of raising embankment for agricultural reservoir.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1008-1011
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• 1996

Most control systems of power plants are using classical PID controllers for their process control. In order to get the desired control performances, the correct tuning of PID controllers is very important. Sometimes, it is necessary to retune PID controllers after the change of system operating condition and system design change, etc. Commercial auto-tuning controllers such as relay feedback controller can be used for this purpose. However, using these controllers to the safety-critical systems of nuclear power plants may be cause of unsafe operation, because they are using test signals for tuning. A new system identification auto-tuning method without using test signal has been developed in this paper. This method uses process input/output signals for system identification of unknown control process. From the model information of control process which was obtained from system identification approach, the optimal PID parameters can be calculated. The method can be used in the safety-critical systems because it is not using test signals during system modeling process.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.1
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• pp.24-28
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• 2014

An induction motor is most widely used to obtain driving force in the industrial field. The induction motor is generated a high current at starting. A starting current is often more than five times of rated current. A high starting current can cause problems such as voltage drop in the power system. In order to solve these problems, a reactor starting method has been widely applied in a large motor capacity. There are differences in the operating characteristics of induction motor corresponding the switching time of reactor tap. In this study, I analyzed that current, torque, power of induction motor are different from changing time and tap setting values of reactor tap.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.518-521
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• 2008

When constructing a high-speed railroad, the reduction of the distance between track centers and the width of track bed will save the construction cost. However the shortening the distance between track centers may cause the stability problems due to higher wind pressure. Therefore the extensive technical review and aerodynamical study should be performed to determine the adequate distance between track centers. In this study, the impact that the increase in wind pressure due to the change of aerodynamic phenomena with the change of the distance between track centers may have on two trains passing by each other was predicted, and the stability of train operation was analyzed in order to review the distance between track centers suitable to Honam HSR trains. And we estimated the aerodynamical effects by the results of the real train experiments by using KTX.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.200-201
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• 2017

Generally, a lot of reinforcements are used in nuclear power plant concrete structures, and it may cause several potential problems when concrete is poured. Because of the congestion caused by hooked bars, embedded materials, and other reinforcements, it is too difficult to pour concrete into structural member joint area. The purpose of this study is to change ACI 349 Code for using the large-size(57mm) and high-strength(Gr.80) headed deformed bars instead of standard hooked bars in nuclear power plant concrete structures in order to solve the congestion problems.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.12 no.1
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• pp.369-386
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• 1999

Recently WHO death from smoking-related illness would increase more than a thousand in the future. But in spite of various harms, smoking cigarette in developing countries is increasing especially in the adolescents. So in order to evaluate whether auricular acupuncture therapy is effective to quit smoking, clinical examination was carried out. And the results showed that age of starting smoking become lower. The cause of smoking is curiosity, relaxation, envy and comradeship. For this reason they want to stop smoking but feel it is difficult to do. Cigarette smoking didn't show any significant change after auricular acupuncture in both control and therapy. And physical and psychological change did not present any significance. However, auricular acupuncture therapy was appeared to be effective to stop smoking. So with these results, further systemic research to examine the effect of auricular acupuncture is seem to be necessary.

• Tribology and Lubricants
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• v.17 no.1
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• pp.10-15
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• 2001

Generally, it is said that the heat generation of air bearing is negligible. But the air bearing using at the built-in spindle is different from the general air bearing itself because of the thermal effects from the spindle motor and high-speed conditions. In this paper, in order to analysis the characteristics of air bearing by the heat, We made easy -heating-bearing-system (EHBS) and hard-heating-bearing-system (HHBS) and could identify the changes between the two bearing systems from the experiments and simulation. When spindle system reached at thermal steady-state, the changes means that the stiffness of air bearing becomes change due to the clearance change between bearing and journal. It is shown that the temperature rise and thermal effects to cause the thormal expansions have to be considered when designing air spindle system.

• Journal of the Korean Society of Costume
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• v.53 no.7
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• pp.37-45
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• 2003

This study is to research the changing trends in the trading goods and the cause of the change in the early Chosun dynasty and to find out the influence that the export goods had on the Chosun society. This research demonstrated the costume culture of the early Chosun was affected by the trading trends. The export items of Chosun showed differences in chronological order. They changed from hemp cloth to cotton cloth. The cause of such change in the export items was due to the change in the amount of demand and supply, to products of Chosun. and to social factors. Looking at the amount and items of the export goods to Japan, the amount was huge and the number of trade was a lot. There were several influences that the exporting cotton cloth to Japan had on Chosun's costume culture. First, the export caused the growth of cotton industry through the reinforcement policy. Next, it made the amount of national deposit of cotton cloth exhausted as a result of the increase in the amount of the exporting cotton. It also made worse the dual distribution structure of cotton cloth and the leaning toward bad cotton cloth. And in consequence of the connection between rich merchants and politicians, these social phenomena became worse and worse. And these facts demonstrate that the costume culture of the early Chosun dynasty was affected by the trade between Chosun and Japan. Therefore, to better understand the costume culture of the early Chosun dynasty, I propose to consider the consequences resulted from the trade with Japan.