• 한국전자통신학회논문지
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• 제11권10호
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• pp.989-994
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• 2016

본 연구는 논에 적용된 수위센서, 송수구 그리고 배수구 장치를 통하여 수위 관리를 수행 한다. 게이트웨이는 LoRa 접속을 통하여 수위센서 물높이 정보를 IoT(: Internet of Thing) 플랫폼에 oneM2M(: Machine to Machine) 규격으로 정보전달 한다. IoT 플랫폼에서 요청하는 물의 높이에 따라서, 게이트웨이는 송수구 또는 배수구 모터 스위치를 On 또는 Off하고 수위센서 정보를 전달한다. IoT 플랫폼은 물높이의 조건에 따라 지능적인 어플리케이션 기능을 수행한다.

• 한국태양에너지학회 논문집
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• 제29권6호
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• pp.1-13
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• 2009

Photovoltaic conditioning systems normally use a maximum power point tracking (MPPT) technique to deliver the highest possible power to the load continuously when variations occur in the insolation and temperature. A unique method of tracking the maximum power points (MPPs) and forcing the boost converter system to operate close to these points is presented through deriving small-signal model and transfer function of boost converter considering input capacitor. This paper aims at modeling boost converter including fairly large equivalent series resistance(ESR) of input reservoir capacitor by state-space-averaging method and PWM switch model and compares both methods using Bode plots. In the future, properly designed controller for compensation will be constructed in 3kw real system for maximum photovoltaic power tracking control.

• Current Optics and Photonics
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• 제1권3호
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• pp.203-206
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• 2017

We report a passive Q-switching of an all-fiber erbium-doped fiber laser delivering high pulse energy by using a high quality single-walled carbon nanotube saturable absorber (SWCNT-SA). A side-polished fiber coated with the SWCNT is employed as an in-line SA for evanescent wave interaction between the incident light and the SWCNT. This lateral interaction scheme enables a stable Q-switched fiber laser that generates high pulse energy. The central wavelength of the Q-switched pulse laser was measured as 1560 nm. A repetition rate frequency of the Q-switched laser is controlled from 78 kHz to 190 kHz by adjusting the applied pump power from 124 mW to 790 mW. The variation of pulse energy from 51 nJ to 270 nJ is also observed as increasing the pump power. The pulse energy of 270 nJ achieved at maximum pump power is 3 times larger than those reported in Q-switched all-fiber lasers using a SWCNT-SA. The tunable behaviors in pulse duration, pulse repetition rate, and pulse energy as a function of pump power are reported, and are well matched with theoretical expectation.

• 한국전기전자재료학회논문지
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• 제28권8호
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• pp.486-489
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• 2015

Power semiconductor device has a very long history among semiconductor, since the invention of low-pressure bipolar transistor 1947, and so far from small capacity to withstand voltage-current, high-speed and high-frequency characteristics have been developed with high function. In this study, the PWM IC Switch to the main parts used in IGBT (insulated gate bipolar transistor) for the low power loss and high drive capability of the simulator to Synopsys' T-CAD used by the 1,700 V NPT Planar IGBT, 1,700 V FS was a study of the Planar IGBT, the results confirmed that IGBT 1,700 V FS Planar is making about 11 percent less than the first designed NPT Planar IGBT.

• 복식
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• 제51권1호
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• pp.33-48
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• 2001

This study is on the sewing construction of the 17th century clothing through the Excavated Costumes in O-chang, ChungBuk in 1998. The followings are the results of this study. There are various sewing constructions in this excavates costume : a running stitch.a back stitch.a half back stitch.a french seam.a gobsol(korean traditional seam sewing). We can see that the sewing construction of the 17th century-clothing depends on construction styles : one layer, two layers, clothing padded with cotton(include quilt). We can see that sewing construction in the one taler clothing consisted of a running stitch, a french seam, a gobsol seam. In the two layer clothing the construction included a running stitch and half back stitch. a running switch and a decorated top stitch(3stitch) were used in the clothing padded with cotton. We can see that the sewing construction enhanced the function of keeping the shape of clothing and the raw edges. We can see that the shape of clothing is important in presentation of aesthetic of the clothing. Such a kind of sewing construction lasted from the early Chosen Dynasty through the 17th century.

• Journal of Biosystems Engineering
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• 제22권4호
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• pp.411-420
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• 1997

The mechanization efficiency using high ability machines such as tractors or combines in a paddy field rice farm is high. Mechanization in harvesting fruits and vegetables is difficult, because they are easy to be damaged. Therefore, Advanced techniques for careful handling fruits and vegetables are necessary in automation and robotization. An apple harvesting robot must have a recognition device to detect the positioning of fruit, manipulators which function like human arms, and hand to take off the fruit. This study is related to the development of a rotatic hand as the first stage in developing the apple harvesting robot. The results are summarized as follows. 1. It was found that a hand that was eccentric in rotatory motion, was better than a hand of semicircular up-and-down motion in harvesting efficiency. 2. The hand was developed to control changes in grasp forces by using tape-type switch sensor which was attatched to fingers' inside. 3. Initial finger positioning was set up to control accurate harvesting by using a tow step fingering position. 4. This study showed the possibility of apple harvesting using the developed robot hand.

• EDISON SW 활용 경진대회 논문집
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• 제6회(2017년)
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• pp.499-505
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• 2017

Photoisomerizing molecules which can transform their structure by the light irradiation have great deal for the application of photo-switching devices. And azobenzene is the representive type of the photoisomerizing molecules. It can transform their trans- structures into cis- structure as the light for certain wave lengths they receive. This property shows the potential of ON/OFF switching functionalization which can be used into the nano scale photo switch. Furthermore, many studies are interested in the organic linkers that connect the azobenzene and metal electrodes. We used S, $CH_2S$, $(CH_2)_4S$ as the linker to watch the influence of linkers for electronic properties. So We suggest a photoswitching device based on the vertical junction using the first-principles calculations with density functional theory and non-equilibrium Greens function (NEGF). By analyzing the electronic structure and tunneling current caused by the structural difference of the system between cis- and trans- azobenzene, the difference in switching mechanism, ON/OFF ratio and transmission will be watched as the linker changes. And finally We will suggest which linker would be the better for the optimal device architecture which can achieve high control of the ON/OFF photocurrent ratio. This result will show the potential of azobenzene-based photoswitch and provide the critical insight in constructing the optimal device architecture.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권3호
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• pp.144-148
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• 2001

For the purpose of developing capacitive humidity sensor having interdigit electrodes, interdigit electrode was modeled and simulated to obtain capacitance and sensitivity as a function of geometric parameters like the structural gap and thichness. For the development of ASIC, switched capacitor signal conditioning circuits for capacitive humidity sensor were designed and simulated by cadence using 0.25um CMOS process parameters. The signal conditioning circuits are composed of amplifier for voltage gain control, and clock generator for sensor driving and switch control The characteristics of the fabricated sensors are; 1) sensitivity is 9fF/%R.H., 2) temperature coefficient of offset(TCO) is 0.4%R.H./$^{\circ}C$, 3) nonlinearity is 1.2%FS, 4) hysteresis is 1.5%FS in humidity range of 3%R.H. ${\sim}$ 98%R.H.. The response time is 50 seconds in adsorption and 70 seconds in desorption. Fabricated process used in this capacitive humidity sensor having interdigit electrode are just as similar as conventional IC process technology. Therefore this can be easily mass produced with low cost, simple circuit and utilized in many applications for both industrial and environmental measurement and control system, such as monitoring system of environment, automobile, displayer, IC process room, and laboratory etc..

• 한국광학회지
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• 제8권6호
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• pp.492-499
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• 1997

굽은 비선형 도파로를 이용한 완전 광 스위치와 굽은 비선형 Y 분기각을 갖는 도파로를 이용한 완전 광 논리 연산소자를 제안하였다. 제안된 완전 광 스위치와 완전 광 논리 연산소자는 굽은 비선형 도파로를 따라가는 비선형파의 전파에 기초를 두고 있다. 빔의 전파특성은 도파로의 비선형성과 입력 파워, 도파로의 굽은 각도 등의 파라미터에 의해 좌우되므로 파라미터를 변화시켜 가면서 파워의 출력 특성을 계산해 보았다. 또한, 비선형 물질로 빠져 나오는 파워를 다양한 위치의 검출기에서 계산함으로써 특정한 검출기의 위치에서 가장 이상적인 디지털 스위칭 특성을 찾았고 도파로 끝과 비선형 물질로 빠져 나오는 파워의 비율에 의해 다양한 논리 함수(AND, OR, XOR)를 구현해 보았다.

• 한국전자통신학회논문지
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• 제5권5호
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• pp.498-503
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• 2010

최근, 전력공급의 안정성과 신뢰성 그리고 고품질화를 위해 인터넷을 기반으로 하는 산업용 디지털 분전반이 새롭게 요구되고 있다. 따라서 본 논문에서는 3상 4선식 전력공급방식을 기반으로 하는 산업용 3상 분전반이 설계된다. 그리고 3상 산업용 분전반을 위한 전력관리 모듈이 시험 제작되며, 끝으로, 3상 전구 부하 시험을 통해 시작품의 3상 전압, 전류 측정 기능이 검증된다.