• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.399-402
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• 2002

In this study, we constructed a four-channel impedance measurement system including a two-channel goniometer to analyze human arm movement. Impedances and joint angles were simultaneously measured for wrist and elbow movements. As the impedance changes resulting from wrist and elbow movements depended heavily on electrode placement, we determined the optimal electrode configurations for those movements by searching for high correlation coefficients, large impedance changes, and minimum interferences in ten subjects (age: 29+6). Our optimal electrode configurations showed very strong relationships between the wrist joint angle and forearm impedance (correlation coefficient = 0.95+0.04), and between the elbow joint angle and upper arm impedance (correlation coefficient = -0.98+0.02). Although the measured impedances changes of the wrist (1.1+1.5 ohm) and elbow (-5.0+2.9 ohm) varied among individuals, the reproducibilities of wrist and elbow impedance changes of five subjects were 5.8+1.8 % and 4.6+1.4 % for the optimal electrode pairs, respectively. We propose that this optimal electrode configuration would be useful for future studies involving the measurement of accurate arm movements by impedance method.

• The Korean Journal of Pain
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• 제29권1호
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• pp.23-28
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• 2016

Background: Sacral nerve stimulation is a therapeutic option with demonstrated efficacy for conditions presenting with perineal pain caused by different etiologies. We aimed to assess whether a sacral electrode ($Interstim^{(R)}$, Medtronic, Minneapolis, MN, USA) inserted through the caudal pathway is able to offer an acceptable level of sacral stimulation and rate of catheter migration. Methods: We present 12 patients with pelvic pain who received sacral neuromodulation via the sacral hiatus with the InterStim electrode. We evaluated patient satisfaction as well as migration and removal of the electrode, if necessary. Results: Our experience included 12 patients, 10 women and two men, with a mean age of 60 years. In eight of the 12 patients, the initial therapy was effective, and the final system implantation was performed. During subsequent follow-up, patient satisfaction was good. To date, there have been no cases of electrode displacement or migration. Conclusions: The caudal insertion of the InterStim electrode, with its own fixation system, and initially designed for transsacral insertion, appears in our experience to be a satisfactory option which can minimize electrode displacements, achieving similar results in therapeutic efficacy and causing no difficulties in removal.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
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• pp.208-212
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• 2001

In this paper, characteristics of the ac and do flashover voltages in the vertical air gap of a needle-plane, sphere-plane and rod-plane electrode system were investigated when the combustion flames were present near the high-voltage electrode. As the results of an experimental we found that the reduction of flashover voltages characteristics with the vertical distance caused, in comparison with the no-flame case were about 1/3 times when a short sap d=1[cm] and 2[cm] of the ac voltages were applied. Also, flashover voltages characteristics of the do negative polarity under sphere-plane and rod-plane electrode system with the combustion flame were increased about two times than those of the do positive polarity.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.93-96
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• 2007

Recently, much attentions have been paid on the commercialization of PEMFC, especially for the applications of residential and portable. In order to achieve the early commercialization of PEMFC, thee are two hurdles to overcome. One is cost down and the other is improvement of durability of the system components. Numerous companies have tried to reduce the production cost and the main research topics have been changed from performance to durability improvement. In this work, acceleration test were performed to find and evaluate the main reason of degradation of the MEA(membrane-electrode assembly) which is one of the core component of the PEMFC system. Based upon the test results, a way to make durable MEA was suggested. Acceleration tests were made by applying high voltage of 1.2V to the several kinds of single cells to increase the growth of catalyst particles. Cell performance, ac-impedance and electrochemically active area measurements were made atfter every 8 hours of acceleration test. Degradations of catalyst and membrane were examined by SEM, TEM and XRD. Obtained results were discussed in terms of structural stability and loss of catalyt and ionomers in the electrode layer. In addition, the way to make highly durable MEA was suggested.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권5호
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• pp.189-193
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• 2003

Initial irreversible capacity (IIC) can be defined by means of the initial intercalation Ah efficiency (IIE) and the initial irreversible specific capacity at the surface (IICs) with the linear-fit range of the intercalation so as to precisely express the irreversibility of an electrode-electrolyte system. Their relationship was IIC = Qc - Q$_{D}$ = (IIE$^{-1}$ - 1) Q$_{D}$ + IICs in the linear-fit range of IIE. Here, Qc and Qd signify charge and discharge capacity, respectively, based on a complete lithium ion battery cell. Charge indicates lithium insertion to carbon anode. Two terms of IIE and IICs depended on the types of active materials and compositions of the electrode and electrolyte but did not change with charging state. In an ideal electrode-electrolyte system, IIE and IICs would be 100%, 0 mAh/g for the electrode and mAh for the cell, respectively. These properties can be easily obtained by the Gradual Increasing of State of Charge (GISOC).OC).

• Journal of Welding and Joining
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• 제15권5호
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• pp.74-83
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• 1997

Effect of welding parameters such as current, speed and electrode pressure on the weld quality of tin coated steels for small containers was discussed in this paper. Welding was performed with low frequency wire seam welding system which was loaded with 1.5mm in diameter copper wire electrode. The welding parameters were monitored at the position close to the welding spot so as to minimize the instrumentation error, and the signals were stored into a digital data acquisition system before analysis. Results showed that critical current for sufficient nugget size increased as the base material thickness increased, while the width of the optimum welding range was reduced. The acceptable welding condition derived from this study was found to be effective within the thickness range of $\pm$10% of the nominal (0.25mm) thickness. Tin coating layer was proved not to affect seriously on the weld quality, i.e. strength and formability, since consumable wire electrode was used in this process. Test results also demonstrated that the welding current was thought to be the most effective parameter to form an acceptable weld, while welding speed or electrode pressure exerted less effect on the nugget formation. However, these two parameters played an important role because the former was related to the nugget overlap interval, and the latter, to the formation of expulsion during welding.

• 한국식품과학회지
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• 제28권5호
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• pp.974-980
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• 1996

멥쌀로 탁주를 제조하여 발효과정 중에 변화되는 에탄올 및 포도당의 함량을 동시에 측정할 수 있는 바이오센서를 dual cathode electrode를 이용하여 제작하였다. Alcohol oxidase와 glucose oxidase는 nylon net에 고정화시켜 anode가 한 개이고 cathode가 두 개인 dual cathode electrode에 부착하여 용존산소가 소모되는 변화량을 측정하여 간접적으로 포도당과 에탄올의 농도를 동시에 측정할 수 있도록 하였다. 이 시스템의 최적 조건은 $35^{\circ}C$에서 pH 7.5인 0.1 M 인산 완충용액이었다. 바이오센서를 이용하여 측정한 값을 분광광도법과 gas chromatography를 이용한 값과 비교해 본 결과 유사한 것으로 나타났다. Dual cathode electrode를 이용한 바이오센서로 측정할 경우 다른 분석방법과 같은 복잡한 전처리 과정없이 두 가지 성분을 동시에 측정하는 것이 가능함으로써 신속하게 측정할 수 있었으며, 탁주와 같은 발효식품의 발효 중 변화하는 두 가지 성분을 동시에 측정할 수 있었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.228.2-228.2
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• 2016

The triggered vacuum switch (TVS) discharges high current through two processes. In the first process, an igniting plasma is generated at a trigger system, and the next process that a main discharge is taken place sequentially at a six-gap rod electrode within a few microsecond. In general, a triggered voltage producing the igniting plasma is increased. However, after several hundred shots, it goes down and stable, in our experiment the trigger voltage is about 5 kV after 250 shots. This triggered characteristics comes from the ceramic insulator which is covered by an electrode material, therefore we have focused on the first igniting plasma process. The igniting plasma has been generated at the surface of a ceramic insulator under a strong electric field. The electric field can be increased through modifying geometries of trigger components which compose of a trigger pin, a ceramic insulator and an enclosed holder. We fabricated not only two types of trigger pin which are a plane head and an umbrella head type, but two different holders which are a concave and a convex type. In this paper the result that the dependency of geometries for these four combined types is included, but the study of the ceramic insulator is not. The research of the ceramic insulator will be announced in the other paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 E
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• pp.1705-1707
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• 1998

In this paper, a superposed discharge type ozonizer was designed and manufactured. The ozonizer is equipped with three electrodes : central electrode, internal electrode and external electrode, and it consists of two gaps. The ozone is generated by superposing silent discharge, which are respectively generated betweens two gaps. This paper describes the following two characteristics : (1) 'the characteristics of discharge with variation with output voltage of AC High Voltage source, quantity of the supplied gas and discharge voltage (2) the characteristics of ozone discharge power, temperature of the supplied gas.

• KSBB Journal
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• 제11권6호
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• pp.669-675
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• 1996

간단한 조작으로 시안화물을 신속하게 계측할 수 있는 센서의 개발을 목적으로 하여 미생물과 산소전극을 이용한 시안센서의 개발을 연구하였다. 산소전극에 S. cerevisiae를 흡착 고정화한 막을 부착하여 막형 시안센서를 제작하고 시료용액중의 시 안이온농도를 O~1.00ppm이 되게 시안을 첨가하면 서 전류값 변화를 살펴본 결과 시안농도 0.10~1.00ppm의 범위에서 응답이 확인되었으며 고정화 직후의 호흡활성은 약 하루정도 유지되었다. S. ceremSlae를 고정화한 키토-펼 HP-5020을 사용하여 반응기형 시안센서를 제작하고 막형 시안센서와 동일하게 시안이온농도 O~1.00ppm 용액의 전 류값 변화를 살펴본 결과 0.10~ 1.00ppm의 범위에서 응답이 확인되었으며 고정화 직후 90%의 호흡활 성이 16일간 유지되었다. 반응기형 시안샌서의 반응기 크기의 영향을 검토 한 결과, 반응기의 최적 체적이 존재한다는 사실을 알 수 있었다.