• 한국전기전자재료학회논문지
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• 제30권6호
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• pp.366-371
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• 2017

In this paper, we introduce an electrocardiogram (ECG) system designed to solve problems caused by wetgels and motion artifacts in measuring active movement. The system is called a dry-contact ECG and was designed by considering impedance matching between skin and electrode as well as the frictional electricity between electrode and clothes. In order to create the system, we measured impedance on the skin-electrode interface, and the result was applied to the electronic circuit scheme. Moreover, we added an electrode on the back of the measurement electrode to make a flow path to ground the electrical noise. The final ECG circuit and novel electrode were used to detect real human cardiac signals from a subject who was tested while standing still and walking. The signals obtained from the two activities were nicely shaped, without any motion artifact noise. We took electrode size into account in this study because the impedance depended on the area of the electrode. An electrode of 50 mm diameter showed the best curve for the ECG signal without any electrical noise.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.1181-1187
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• 2015

Sulfur hexafluoride (SF₆) gas is used widely in electric power equipment such as Gas Insulated Switchgear (GIS), Gas Insulation transmission Line (GIL), and Gas Circuit Breaker (GCB). But applications of SF₆ should be restricted because SF6 gas is one of the greenhouse effect gases. To reduce use of SF₆ gas, a study on eco-friendly alternative insulation medium is needed. In this paper, we investigated lightning impulse (LI) breakdown of dry-air which is attracting attention as an ecofriendly alternative gas and the LI breakdown of hybrid insulation combined with dry-air and solid insulation (Room-Temperature Vulcanizing Silicone Rubber-RTV SIR) and dry-air in inhomogeneous fields according to gap distance and pressure. The experiment results showed that the LI breakdown strength of hybrid insulation system was higher than that of dry-air insulation system. It was verified that the development of technology related to eco-friendly power apparatus compact such GIS, GCB and GIL can be used as basic research data.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.247-249
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• 2007

This paper proposes a dry-type surface myoelectric sensor for the myoelectric hand prosthesis. The designed surface myoelectric sensor is composed of skin interface and processing circuits. The skin interface has one reference and two input electrodes, and the reference electrode is located in the center of two input electrodes. Considering the conduction velocity and the median frequency of the myoelectric signal, the inter-electrode distance (IED) between two input electrodes as 18mm, 20mm, and 22mm is selected. The signal processing circuit consists of a differential amplifier with a band pass filter, a band rejection filter for rejecting 60㎐ power-line noise, amplifier, and a level circuit. Using SUS440, six prototype skin interface with different reference electrode shape and IED is fabricated, and their output characteristics are evaluated by output signal obtained from the forearm of a healthy subject. The experimental results show that the skin interface with parallel bar shape and the 18mm IED has a good output characteristics. The fabricated dry-type surface myoelectric sensor is evaluated for the upper-limb amputee.

• Transactions on Electrical and Electronic Materials
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• 제14권1호
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• pp.28-31
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• 2013

A volcano shaped gated Si-FEA (silicon field emitter array) was simply fabricated using sputtering as a gate electrode deposition and lift-off for the removal of the oxide mask, respectively. Due to the limited step coverage of well-controlled sputtering and the high aspect ratio in Si dry etch caused by high RF power, it was possible to obtain Si FEAs with a stable volcano shaped gate structure and to realize the restriction of gate leakage current in field emission characteristics. For 100 tip arrays and 625 tip arrays, gate leakage currents were restricted to less than 1% of the anode current in spite of the volcano-shaped gate structure. It was also possible to keep the emitters stable without any failure between the Si cathode and gate electrode in field emission for a long time.

• 한국전기전자재료학회논문지
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• 제16권8호
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• pp.731-735
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• 2003

Ti-indiffused LiNbO$_3$waveguide have been used to various high speed optical device based on electro-optic effect such as modulators, switches, and sensor, etc. In order to high speed modulation of optical modulator have, one of the further devices, needed to increasing of electrode surrounding air by LiNbO$_3$dry etching because of impedance matching for optical and RF phase velocity between waveguide and electrode. We studied property of LiNbO$_3$dry etching after waveguide patterning lot optical modulation by using neutral loop discharge (NLD) plasma.

• 한국정보통신학회논문지
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• 제13권7호
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• pp.1393-1398
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• 2009

본 연구는 LCD용 비정질 실리콘박막트랜지스터의 제조공정중 가장 중요한 식각 공정에서 각 박막의 특성에 맞는 습식 및 건식식각공정을 개발하여 소자의 특성을 안정시키고자 한다. 본 연구의 수소화 된 비정질 실리콘 박막 트랜지스터는 Inverted Staggered 형태로 게이트 전극이 하부에 있다. 실험 방법은 게이트전극, 절연층, 전도층, 에치스토퍼 및 포토레지스터층을 연속 증착한다. 스토퍼층을 게이트 전극의 패턴으로 남기고, 그 위에 n+a-Si:H 층 및 NPR(Negative Photo Resister)을 형성시킨다. 상부 게이트 전극과 반대의 패턴으로 NPR층을 패터닝하여 그것을 마스크로 상부 n+a-Si:H 층을 식각하고, 남아있는 NPR층을 제거 한다. 그 위 에 Cr층을 증착한 후 패터닝 하여 소오스-드레인 전극을 위한 Cr층을 형성시켜 박막 트랜지스터를 제조한다. 여기서 각 박막의 패터닝은 식각 공정으로 각단위 박막의 특성에 맞는 건식 및 습식식각 공정이 필요하다. 제조한 박막 트랜지스터에서 가장 흔히 발생되는 문제는 주로 식각 공정시 over 및 under etching 이며, 정확한 식각을 위하여 각 박막에 맞는 식각공정을 개발하여 소자의 최적 특성을 제공하고자한다. 이와 같이 공정에 보다 엄격한 기준의 건식 및 습식식각 공정 그리고 세척 등의 처리공정을 정밀하게 실시하여 소자의 특성을 확실히 개선 할 수 있었다.

• 한국분말재료학회지
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• 제27권4호
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• pp.305-310
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• 2020

In this study, partially dry transfer is investigated to solve the problem of fully dry transfer. Partially dry transfer is a method in which multiple layers of graphene are dry-transferred over a wet-transferred graphene layer. At a wavelength of 550 nm, the transmittance of the partially dry-transferred graphene is seen to be about 3% higher for each layer than that of the fully dry-transferred graphene. Furthermore, the sheet resistance of the partially dry-transferred graphene is relatively lower than that of the fully dry-transferred graphene, with the minimum sheet resistance being 179 Ω/sq. In addition, the fully dry-transferred graphene is easily damaged during the solution process, so that the performance of the organic photovoltaics (OPV) does not occur. In contrast, the best efficiency achievable for OPV using the partially dry-transferred graphene is 2.37% for 4 layers.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.770-772
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• 2002

A new dry-processing method of organic gate dielectric film in field-effect transistors (FETs) was proposed. The method use vapor deposition polymerization (VDP) that is continuous and low temperature process. It has the advantages of shadow mask patterning and dry processing in flexible low-cost large area applications. Here, 80 nm-thick Al as a gate electrode was evaporated through shadow mask. Gate insulators used two different polyimides. The one material was 4,4'-oxydiphtahlic anhydride (ODPA) and 4,4'-oxydianiline (ODA). Another was 2,2-bis(3,4-dicarboxyphenyl) Hexafluoropropane Dianhydride (6FDA) and 4,4' -oxydianiline (ODA). These were co-deposited by high-vaccum thermal-evapora and cured at 150 $^{\circ}C$ for 1 hour, respectively. Pentacene as a semiconductor and 100 nm-thick Au as a source and drain electrode were evaporated through shadow mask.

• 정보통신설비학회논문지
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• 제10권3호
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• pp.92-97
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• 2011

In this paper, a controller recognizing human gestures using EMG signal is shown. The tiny and band-type controller is developed for image training to excercise the specific area in the body, and uses a dry-type silver fiber electrode easy to be attached or detached itself to a skin. The captured EMG signals are converted to 10-bit digital values via amplification and frequency filtering processes within the controller, and are transmitted to the server by wireless. As the gesture recognition ratio using the proposed controller on biceps is up to 80%, we expect the practical potential of the controller is very promising.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1400_1401
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• 2009

In this paper describes the comparisons of the surface flashover characteristics according to the change of the insulation media by experimental GIS(Gas Insulated Switchgear) chamber in accordance with change of pressure(P) and electrode distance(d). The using insulation medias are $SF_6$, Dry-Air, I-Air(Imitation Air, $N_2$ : $O_2$ = 79[%] : 21[%]), $N_2:O_2$ mixture gas and pure $N_2$. In this study, in order to compare the properties $SF_6$ and order insulation gas, we investigated the properties of the various insulation media with a knife to knife electrode under ac high voltage application. The gas pressure was changed from 1 to 5[atm]. as a result, it was found that dielectric strength is $SF_6$ > I-Air > Dry-Air and the best environmental preservation gas is Dry-Air.