• 한국기계가공학회지
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• 제15권2호
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• pp.118-124
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• 2016

In this study, experiments are conducted to improve spray coating uniformity by using second and third electrodes based on the electrospray atomization mechanism. The uniformity of fabricated thin films can be improved by adjusting the design of the second electrode. The implementation of the second electrode with an elongated hole and a bending angle of $90^{\circ}$ results in highly uniform films. In addition, induced area to substrate is increased by lowering the applied voltage using the third electrode with a round rod shape. A linear correlation between applied voltage and induced area is confirmed. Thin film thickness and surface roughness are measured after the fabrication of thin films through the electrospray process. It is confirmed that a thin film is formed having an average thickness of 273.44 nm, a thickness uniformity of less than 10%, and a surface roughness of 3 nm.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.247.1-247.1
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• 2014

The capacitive coupled plasma is used widely in the semiconductor industries. Especially, the uniformity of the industrial plasma is heavily related with defect ratio of devices. Therefore, the industries need the capacitive coupled plasma source which can generate the uniform plasma and control the plasma's uniformity. To achieving the uniformity of the large area plasma, we designed multi-powered electrodes. We controlled the uniformity by controlling the power of each electrode. After this work, we started to research another concept of the plasma device. We make the plasma chamber that has multi-ground electrodes imaginary (CST microwave studio) and simulate the electric field. The shape of the multi-ground electrodes is ring type, and it is same as the shape of the multi-power electrodes that we researched before. The diameter of the side electrode's edge is 300mm. We assumed that the plasma uniformity is related with the impedance of ground electrodes. Therefore we simulated the imaginary chamber in three cases. First, we connected L (inductor) and C (capacitor) at the center of multi-ground electrodes. Second, we changed electric conductivity of multi-ground electrode. Third, we changed the insulator's thickness between the center ground electrode and the side ground electrode. The driving frequency is 2, 13.56 and 100 MHz. We switched our multi-powered electrode system to multi-ground electrode system. After switching, we measured the plasma uniformity after installing a variable vacuum capacitor at the ground line. We investigate the effect of ground electrodes' impedance to plasma uniformity.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1529_1530
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• 2009

The process conditions for fabricating p-type silicon pillars were optimized by controlling current density, bath temperature. To get best process flexibility for pillar arrays formation, three factors affecting pillar formation were changed. First, the solution bath was designed to keep constant temperature during the experiment irrespective of external temperature. Second, the counter Pt electrode was changed from rod type to mesh to obtain uniform distribution of current density. Third, Cr-Cu alloy electrode instead of Cu was used to increase electrode current density.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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• pp.71-74
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• 2002

In this study, resonant characteristics of $Pb_{0.88}(La_{0.6}Nd_{0.4})_{0.08}(Mn_{1/3}Sb_{2/3})_{0.02}Ti_{0.98}O_3$ ceramics were investigated with the variations of electrode radius size for manufacturing the best 30MHz SMD type ceramic resonator with the size of $3.7{\times}3.1{\times}0.255mm^3$. Physical properties were proper for appling for 30MHz SMD type ceramic resonator. In third overtone thickness vibration mode, with increasing electrode radius size, resonant resistant($Z_r$) was decreased gradually. Mechanical quality factor($Q_{mt3}$) and dynamic range(D.R) showed the maximum value of 2,283, 47.1dB respectively, at 0.74mm electrode radius size.

• 한국전기전자재료학회논문지
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• 제28권1호
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• pp.34-39
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• 2015

In this study, the characteristics of partial discharge was measured for the four core silicone cable (0.6/1.0 kV, $1.0SQ{\times}4C$) with insulated part of 15 cm and conductor of 1cm. The following results have been confirmed as a result of this study. When the first line of cable is connected to the positive electrode and the second, third line of cable is connected to the negative electrode, it found that the inception voltage and extinction voltage decreased with increasing the line of negative electrode, and the partial discharge charge quantity(Q) increases, while the number of discharge occurrence has decreased. The inception voltage and extinction voltage of partial discharge has decreased with increasing the degradation rate in the 33%, 67%, 100%. Also, it confirmed that the partial discharge charge quantity(Q) and the number of discharge occurrence has decreased.

• The Korean Journal of Pain
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• 제19권2호
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• pp.244-248
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• 2006

Radiofrequency lesioning is a valuable tool for third occipital headache. Relative to most neural targets, a radiofrequency lesion is very small. Reliable pre-operative diagnosis of the nociceptive source is critical, as inappropriately placed lesions will not modulate pain. Knowledge of the anatomical courses of nerves and extremely precise electrode placement are required for accurate lesioning. This report describes our experience with RF lesioning in the treatment of chronic pain in two patients who suffered from third occipital headaches. In one patient, satisfactory improvement of the pain was observed after 10 months of follow up.

• 한국운동역학회지
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• 제30권1호
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• pp.103-109
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• 2020

Objective: The purpose of this study is to compare the muscle activity by electrode location in the biceps brachii during the arm curl isometric exercise and to provide the basic data needed to develop the proper electrode location of the biceps brachii based on the study results comparing the muscle activity by the angle of the elbow joint. Method: 17 adult males (Age: 21.50±4.63 yrs, height: 175.29±5.97 cm, weight: 63.79±15.31 kg, upper-arm length: 30.10±1.22 cm) participated in the study. In the arm curls isometric exercise, the experiment was divided into 1st and 2nd steps to compare muscle activity according to electrode location in the biceps brachii and muscle activity according to elbow angle change. In the first experiment, the surface electrode was attached at one-third point on the line from medial acromion to cubital fossa, according to the measurement method indicated by SENIAM. The elbow angle was set to 90°. In the second experiment, according to the proposed method of this study, the electrodes were separated at one finger's width in the left and right direction at one-third point on the line from medial acromion to cubital fossa, attached at the long head and short head. From the long head electrode, in about a width of two fingers in proximal direction, a total of three electrodes were attached at the myotendinal junction of the long head. The elbow angles were set as 70°, 90°, and 110°, and the isometric exercise (100% MVC) for 5 seconds was maintained with keeping the forearm and the rope to be 90° for the first and second experiments. Results: During the arm curl isometric exercise, there was no significant difference in SH and SENIAM proposition location proposed by this researcher. LH was shown to be lower than the muscle activity of the location proposed by SENIAM and there were significant (p<.01) differences. MJ appeared lower than the muscle activity of the location proposed by SENIAM and there were significant (p<.001) differences. The muscle activity by the elbow joint angle of SH in the biceps brachii was shown in large order of 70°<90°<110°, but there was no significant difference. The muscle activity by the elbow joint angle of LH was shown in large order of 90°<70°<110°, but there was no significant difference. The muscle activity by the elbow joint angle of MJ was shown in large order of 110°<90°<70°, but there was no significant difference. Conclusion: During the arm curl isometric exercise of the biceps brachii, it is judged appropriate to attach surface electrodes to the location proposed by SENIAM.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권2호
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• pp.79-85
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• 2001

A conventional electrolyzing cell has been made by an ion exchange membrane inbetween parallel plate electrodes. A low dc voltage is applied to the electrodes for electrolyzing and the efficiency is remained in low. in this study, a novel electrolyzing cell with a pair of slit-type third electrodes installed inbetween parallel plate electrodes has been proposed and investigated experimentally. And pulse power wa supplied to between each electrodes. This slit type of third electrodes can concentrate the strong electric fields at the every its edges to accelerate the electrolyzing powers, and to generate oxygen bubble discharges for generating oxidants. And moreover the slits eliminate the space charge limiting action and the temperature of the water by leaking out through the slits from electrolyzing region to outside of the main electrode region. As a result, it was found that a strong electorzed water of pH 2.8 and pH 10.5 and oxidants dissolved water of 1 [ppm] in acidic water were obtained with a tap water fed at the electric current of 2 [A], which however were several times higher oxidant and ion concentration quantity compared with the conventional cell.

• Journal of Korean Neurosurgical Society
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• 제43권2호
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• pp.85-89
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• 2008

Objective: The purpose of this study is to identify the factors affecting the failure of trials (<50% pain reduction in pain for trial period) to improve success rate of spinal cord stimulation (SCS) trial. Methods: A retrospective review of the failed trials (44 patients, 36.1 %) among the patients (n=122) who underwent SCS trial between January 1990 and December 1998 was conducted. We reviewed the causes of failed trial stimulation, age, sex, etiology of pain, type of electrode, and third party support. Results: Of the 44 patients, 65.9% showed unacceptable pain relief in spite of sufficient paresthesia on the pain area with trial stimulation. Four of six patients felt insufficient paresthesia with stimulation had the lesions of the spinal cord. Seventy five percent of the patients experienced unpleasant or painful sensation during stimulation had allodynia dominant pain. Third-party involvement, sex, age and electrode type had no influence on the outcome. Conclusion: We conclude that SCS trial is less effective for patients with neuropathic pain of cord lesions, postherpetic neuropathy or post-amputation state. Further, patients with allodynia dominant pain can feel unpleasant or painful during trial stimulation.

• 한국생산제조학회지
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• 제26권3호
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• pp.285-291
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• 2017

Micro-needles are used as transferring devices for sampling of tiny constitute substances from biological bodies. Typically, nickel is used as a coating to improve the rigidity of micro-needles. This study introduces the methodology to manufacture a WC needle with very high hardness and toughness. Micro-EDM technology was used to manufacture micro-needles with holes $130{\mu}m$ in diameter and $2300{\mu}m$ in length. A micro-needle was aligned to the micro-EDM electrode using a custom two degree-of-freedom alignment system. A three-step manufacturing technique was developed to drill a micro-hole using a WC electrode. In the first process, an electrode $105{\mu}m$ in diameter was used to make a hole. Electrodes of 90 and $105{\mu}m$ diameters were used in the second and third process, respectively. Consequently, a WC micro-needle with an inner hole of $135{\mu}m$ diameter, length of $2300{\mu}m$, and outer diameter of $300{\mu}m$ was developed.