• The Journal of the Acoustical Society of Korea
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• v.16 no.5
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• pp.12-17
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• 1997

In this work, we developed a new type ultrasonic dehumidifier with piezoelectric ceramics, which and efficiently repel waterdrops on outdoor glass plates exposed to raindrops. Through finite element analysis of a certain type of glass plates to analyze its dynamic behavior, the structure of the ultrasonic device we determined to get the optimal performance. A supplemental metal plate was attached to the glass plate for uniform cleaning. Based on the theoretical results, experimental samples were fabricated and evaluated with various dimensions of the glass plate and the piezoceramic vibrator. Driving circuit for the dehumidifier made use of the frequency sweeping technique to keep track of the resonant frequency of the glass plate that was variant with environmental conditions.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.132-132
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• 1999

카본 박막은 내마모성, 내산성, 윤활성 및 높은 경도를 가지고 있어, 경질 박막 및 기능성 박막으로 주목을 받고 있으며 그 응용 분야가 매우 크다. 본 연구는 전자빔(Electron Beam)을 카본 grain을 증발시킴과 동시에 아르곤 보조 이온빔을 조사시켜 이온에너지에 따른 박막의 물성변화를 관찰하였다. 특히 본 연구에서 이용한 이온빔 증착 장치의 장점은 이온 충돌 에너지의 조절이 가능하다는 것이다. 카본 박막의 제조는 이온빔이 증착된 고진공 증착 장치를 이용하였고 이원빔원으로는 Oxford Applied Research 사의 RF 방전형 이온빔을 이용하였다. 배기장치는 유회전펌프와 터보펌프를 사용하였다. 기판은 홀더에 장착하기 전에 전처리를 거친 후 용기 내에서 이온빔에 의해 2차 청정을 하였다. 빔전압이 500V, 빔 전류는 4mA/cm2 및 RF power를 400W로 하여 기판 청정을 거친 후 전자빔을 이용하여 흑연을 증발시켜 박막을 제조하였다. 이때 이온빔 전압을 100~500V, RF power를 400~550W 으로 조절하였다. 카본 grain을 Si 및 Slide Glass 기판위에 1$\AA$/sec의 증착율을 유지하면서 증착하였다. 카본 박막의 박막은 평균두께는 0.3~0.4$\mu\textrm{m}$이며 SEM을 이용하여 단면을 관찰하였다. 라만 분광분석을 통하여 비정질 카본 박막의 결합특성을 조사하였고 scratch tester를 이용하여 박막의 밀착력을 관찰하였다. 그리고 카본 박막의 전도도 특성을 알고자 비저항을 측정하였으며, 박막의 성분 분석을 위한 AES 분석을 하였다. 1)AES 결과:표면에서와 박막 내부에서는 불순물인 산소나 질소의 함량이 거의 존재하지 않음을 관찰하였다. 2)경도:1,000~1,400kg/mm2 3)라만 분광 분석:300V의 이온 에너지를 분기로 박막 구조의 변화에 의한 스팩트럼의 변화를 보였다. 4)비저항:10-2~10-1$\Omega$.cm

• Journal of the Korean Institute of Telematics and Electronics
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• v.15 no.5
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• pp.19-24
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• 1978

In this paper, the functional propertied of vibrotactile sense of skin were studied by means of psycophysical experiments with respect to frequency and waveform of mechanical vibration, two-point threshold, contactor size of stimulators. Furthermore, leased on the experimental result, a small vibrotactile stimulator made of piezoelectrc ireed vibrator array was proposed for a aid blind to recognition of the Korean letters. A tactile output image is presented by an 8 row$\times$1 column array of samall vibrator reeds with 200 Hz rectangular wave, the array fitting on a fore-finger. Under the control of the NOVA mini-computer, the bimorph reeds array could represent any of one of the 24 characters of the Korean vowel and consonant at the 8 positions from left to right on the array. Without learning effect, the identification test of the Korean characters by the designed experimental system was carried out. The average rate of correct response was 90%.

• Journal of Chest Surgery
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• v.43 no.2
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• pp.168-171
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• 2010

The number of cases of extracorporeal membrane oxygenation (ECMO) has rapidly increased all over Korea since the introduction of peripheral cannulation catheters. However, the application of ECMO to children has been limited due to the shortage of pediatric equipment and difficulty in maintaining an ECMO system with peripheral cannulation. For this reason, there have been only few reports of pediatric ECMO in Korea, and most of them pertained to the veno-arterial type ECMO for supporting the cardiac system in postcardiotomy patients. We report here on the successfully performing veno-venous ECMO, with using a double lumen percutaneous catheter, in a child with acute respiratory distress syndrome.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.2
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• pp.62-68
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• 1998

In this paper, we proposed the design of the intelligent traffic control system by using multiprocessor architecture. The inter-processor communication of the architecture is implemented by sharing the serial communication channel. In comparing the conventional traffic control system using single processor architecture, the proposed system uses multiple processors controlling the sub systems such as the signal lights, traffic measurement unit, auxiliary signal lights and peripherals. The main processor controls the communication among the processors and the communication protocol link to the central control center at remote site. The proposed architecture reduces the load and simplifies the program of each processor and enables the real time processing of the add-on features of intelligent traffic control systems. The architecture is implemented and the common channel inter-processor communications and the real time operation is experimented .experimented .

• Korean Journal of Occupational Therapy
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• v.26 no.4
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• pp.85-95
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• 2018

Objective : The purpose of this study was to investigate the awareness and availability on items of 2018 assistive devices distribution program for the disabled in the occupational therapists. Methods : A total of 132 occupational therapists participated in the survey from May 1 to May 31. Results : 96.2% of the occupational therapists responded that assistive device is helpful in lives of the disabled people. Especially, they responded that assistive device is the most helpful in 'movement and mobility'. Awareness on an angle spoon/fork with built-up handle and universal cuff was the highest, while a visual signaling indicator was the lowest. Availability on an air cushion was the highest, while a visual signaling indicator and a voice guidance system were the lowest. 67.4% responded that 'sometimes' they use the assistive device and 77.3% responded they will utilize the assistive device. To improve awareness and availability, 43.2% needed financial support, 32.6% needed to add insurance bill and 22.7% needed related education. Conclusion : In the future, this result will be available as a basic data for the education about assistive device for the occupational therapists.

• Smart Media Journal
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• v.4 no.2
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• pp.17-25
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• 2015

In this paper proposes an idea for using NFC(Near Field Communication) on smalt mobile devices, you can easily control the electric wheelchair system. In this system with previous researches controlled a power wheelchair in a mobile device using Bluetooth communication, the board communicates with the integrated control of the wheelchair. With smart mobile devices, the wheelchair control board integrating the signal generated by checking real time so that the user can easily monitor the state of the wheelchair. Users are using smalt mobile devices, the wheelchair can be controlled easily, and the setting at any time according to the state of the individual and can be used. HEX format control is directly in hardware, allowing analysis was read, the user settings are typically used to match cards which support NFC technology such as bus card for registration, storing the selected information and enable read and were applicable. By applying this system, wheelchairs oriented aids disabled and older people able to access to provide with stability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.336-342
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• 2018

Noise reduction is an important issue in auxiliary power unit(APU) of tracking equipments for using military. In this study, we designed and tested reduction methods of structure borne noise and airborne source noise at the auxiliary power unit. From the bench test results, it is found that the effect of noise reduction is about 22 dB(A) if the silencer is redesigned, which is the rescue structure. However, the influence of noise reduction by air is insufficient. In addition, it is confirmed that the effect of noise reduction is excellent when structure borne noise reduction is applied to the vehicle. We expected that the test results of this study are used as basic data to reduce the noise of other tracking equipment developed later.

• Fire Science and Engineering
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• v.20 no.1 s.61
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• pp.71-76
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• 2006

The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The occurrence factor of the fire is electric arc or spark accompanied with electrical faults. Residual Current Protective Device(RCD) of high sensitivity type used at low voltage wiring cuts off earth leakage and overload, but the RCD can't cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied low voltage distribution panel are prescribed to rated breaking time about 30[ms](KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To be improved on such problem, this paper is proposed to a auxiliary control apparatus for RCD trip on electric arc or spark due to electrical fire. Some experimental results of the proposed apparatus is confirmed to the validity of the analytical results.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.1
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• pp.94-99
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• 2007

Many cases of acute cardiac shock and cardiac arrest in emergency room and ICU have been increasing. In this case, ECMO with centrifugal pump has been used generally. However, due to the heavy weight and big size, the system is not adequate for emergency cases. And other defects of this system are that membrane oxygenator's pressure is high and blood are exposed to the air. There was some tries of ECMO using pulsatile pump, but it was found that the weak point of these system is high peak pressure and hemolysis. The mechanism of twin pulsatile pump is that Membrane oxygenator Outlet Pump(MOP) make negative pressure when Membrane oxygenator Inlet Pump(MIP) provides high positive pressure, and the negative pressure will decrease positive pressure of Membrane Oxygenator. Our group analyzed this advantage through In-Vitro and 12 Cases In-Vivo test.