• Journal of Korean Physical Therapy Science
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• v.2 no.1
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• pp.423-429
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• 1995

• Journal of the Korean Electrochemical Society
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• v.11 no.3
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• pp.154-158
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• 2008

The synthesis of hollow ${Sb_93}{Pt_7}$ nanospheres smaller than 30 nm with a shell consisting of smaller nanoparticles, with an average particle size of ${\sim}$ 3 nm is reported. The formation of this alloy is driven by galvanic replacement reaction involving Sb nanoparticles and ${H_2}{PtCl_6} $ without need for any additional reductants. Further, the reaction proceeds selectively as long as the redox potential between two metals is favorable. The capacities of the hollow samples are 669 and 587mAh/g at rates of 1 and 7C, respectively, while those values for the nanoparticles are 647 and 480mAh/g at rates of 1, 7C, respectively. This result shows the significantly improved capacity retention of the hollow sample at higher C rates, indicating that high surface area of the hollow nanospheres makes the current density more effective than that for the solid counterpart.

• Journal of the Korean Society of Safety
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• v.35 no.1
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• pp.62-69
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• 2020

Most people suffer from stress during day life because modernized society is very complex and changes fast. Because stress can affect to many kind of physiological phenomena it is even considered as a disease. Therefore, it should be detected earlier, then must be released. When a person is being stressed several bio-signals such as heart rate, etc. are changed. So, those can be detected using medical electronics techniques. In this paper, stress assessment system is studied using random forest algorithm based on heart rate, RR interval and Galvanic skin response. The random forest model was trained and tested using the data set obtained from the bio-signals. It is found that the stress assessment procedure developed in this paper is very useful.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.543-548
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• 2001

The corrosion monitoring methods of reinforcing steel in concrete are the various methods such as half cell potential method, galvanic current method, resistivity method, polarization resistance method, AC impedance method and etc. In this study, the corrosion monitoring methods of reinforcing steel in concrete were investigated for the test specimens using corrosion inhibitors, zinc-mortar, zinc-plate, respectively. For this purpose, the accelerated corrosion tests for reinforcing steel were conducted according to the periodic cycles(140 days) of wetting($65^{\circ}C$, 90% R.H.) and drying period(15$^{\circ}C$ , 65% R.H.) for the test specimens. As a result, it can be concluded from the test that half cell potential and galvanic current method as monitoring techniques for corrosion were found to be relatively reliable and easily usable method in the field.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1277-1287
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• 2016

This study proposes a novel isolated high step-up galvanic converter, which is suitable for renewable energy applications and integrates a boost converter, a coupled inductor, a charge pump capacitor cell, and an LC snubber. The proposed converter comprises an input inductor and thus features a continuous input current, which extends the life of the renewable energy chip. Furthermore, the proposed converter can achieve a high voltage gain without an extremely large duty cycle and turn ratio of the coupled inductor by using the charge pump capacitor cell. The leakage inductance energy can be recycled to the output capacitor of the boost converter via the LC snubber and then transferred to the output load. As a result, the voltage spike can be suppressed to a low voltage level. Finally, the basic operating principles and experimental results are provided to verify the effectiveness of the proposed converter.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.11a
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• pp.71-73
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• 2003

본 연구에서는 안정 상태에서 일반 공기 중에 산소 농도(21％) 환경에 비해 외부에서 고 농도(35％)의 산소 공급이 혈중 산소 포화도(SPO2), 심박동율(Heart rate), 피부전도도(Galvanic skin response)에 어떠한 영향을 미치는지를 검증하고자 한다. 35％의 고농도 산소를 2L/min의 양으로 일정하게 공급할 수 있는 산소 공급 장치를 이용하였고, 뇌 질병이 없는 5명의 대학생들이 피험자로 참여하였다. 21％의 비해 35％ 산소 농도에서 모든 실험 참여자의 3분 동안의 평균 심박동율은 감소하였고 평균 혈중 산소 포화도는 증가하였다. 그러나 피부전도도는 차이가 없었다.

• Journal of Welding and Joining
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• v.18 no.3
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• pp.97-105
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• 2000

The stress corrosion cracking(SCC) and hydrogen embrittlement cracking(HEC) characteristics of a weathering steel weldment were investigated in aerated acid-chloride solution. The electrochemical properties of weldment were investigated by polarization test and galvanic corrosion test. Weathering steel did not show passive behavior in the acid-chloride solution. Galvanic corrosion between the weld metal and the base metal was not observed because the base metal was anodic to the weld metal. The slow-strain-rate tests(SSRT0 were conducted at a constant strain rate o 7.87×{TEX}$10^{-7}${/TEX}/s at corrosion potential, and at potentiostatically controlled anodic and cathodic potentials. The weldment of weathering steel was susceptible to both anodic dissolution SCC and hydrogen evolution HEC.

• Journal of the Korean Ceramic Society
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• v.38 no.6
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• pp.499-505
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• 2001

The behaviour of ionic compound crystals under combined chemical and externally applied electrical potential gradients is discussed. Firstly, a systematic overview is given. Then a formal analysis follows. The transport equations of the ions and the electric defects predict that even with reversible electrodes demixing, and in particular decomposition of the compound will occur if the applied d.c. current density is sufficiently high. These predictions are illustrated by appropriate experiments. With the help of the solid solution (Me, Fe)O, where Fe-ions are the dilute species, we investigate experimentally the behaviour of a ternary ionic crystal under a d.c. electric current load. All the compounds were placed in a galvanic cell, and the internal reactions which then could be observed were driven by the electric field in this cell. In addition, we discuss the influence of the electric field on the classical solid state reaction AX+BX=ABX$_2$, if again the reaction couple is placed in a galvanic cell.

• Journal of Korea Foundry Society
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• v.37 no.3
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• pp.63-70
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• 2017

In the present study, effects of an addition of Sn on the microstructure and corrosion behavior were investigated in Mg-4%Zn-(0-3)%Sn casting alloys. With an increase in the Sn content, the ${\alpha}-(Mg)$ dendritic cell size was reduced, whereas the total amount of precipitates increased due to the formation of the $Mg_2Sn$ phase. It was found in immersion and electrochemical corrosion tests that the addition of Sn has a detrimental effect on the corrosion resistance of the Mg-4%Zn alloy. Microstructural examinations of the corrosion product and the corroded surface indicated that an accelerated micro-galvanic effect by the $Mg_2Sn-phase$ particles and a less protective corrosion product on the surface were responsible for the increased corrosion rate at a higher Sn content.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.6
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• pp.806-813
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• 1999

The effect of Post-Weld Heat Treatment(PWHT) of SS400 Steel was investigated with parameters such as micro vickers hardness corrosion potential polarization behaviors galvanic current Al anode generating current Al anode weight loss etc. Hardness of each parts(HAZ, BM, WM)by PWHT is lower than that of each parts by Non Post-Weld Heat Treatment(NPWHT) However hardness of WM of HAZ part was the highest among those three parts and HAZ area were also acted as cathode without any case of heat treatment. Potential difference between each three parts by PWHT was also smaller compared to NPWHT. Therefore it is suggested that Corrosion resistance property is increased by PWHT. However both Al anode generating current and anode weight loss was also decreased by PWHT compared to NPWHT when SS400 steel is cathodically protected by Al anode.