• 한국농공학회논문집
• /
• 제62권6호
• /
• pp.111-118
• /
• 2020

This study developed a rainwater harvesting system for the irrigation of upland on sloping area. The assessment of water supply capacity was evaluated in farm field experience. This system consists of a water catchment device and a collapsible storage tank. The water catchment device was designed to collect runoff water in natural channel of 500 mm width into a pipe of 50 mm inner diameter. The device has funnel-shaped plan and cross-section of square. The storage capacity of the collapsible water tank was caculated to meet the water demand for irrigation in 30 a cultivated land for 10-year frequancy drought. The tank has a cuboid shape with a capacity of 30 ㎥, 5 m in width and length, 1.2 m in height. This system can supply 92% of the water required for drop irrigation of red pepper and 88% of the water required for drop irrigation of onions in 30 a cultivation land during the month of May and June. In the case of 16-dry days of 10-years frequency, this system is capable to irrigate 100% of required water for red pepper and onion, 76.7% of required water for Omija (Schisandra chinensis), and 51.5% of required water for autumn kimchi cabbage.

• Archives of Plastic Surgery
• /
• 제36권4호
• /
• pp.445-449
• /
• 2009

Purpose: A successful surgical treatment for a wide alveolar cleft with bone graft is difficult to achieve due to several factors such as the limitation of gingivoperiosteal flap, the presence of large scar tissues, and the poor blood circulation. To overcome these problems, alveolar distraction osteogenesis using Liou alveolar distraction device was applied. We analyzed the consequences of this surgical treatment. Method: Between 2006 January and 2007 August, we have conducted analysis on the methods and consequences of Liou alveolar distraction osteogenesis for 6 patients. The age of patients was 12 years and 6 months in average. The follow up period was 19 months in average. The Reverse L osteotomy followed by the placement of the Liou alveolar distraction device was performed. After serial distraction, the distractor was removed after 5 months of the process of osteogenesis, and the result was analyzed using the computed tomography and the x-ray films of the alveolar bone and the teeth. Results: The alveolar cleft with 12.5 mm in average width was filled with 8.5 mm of newly formed bone tissue in average width after 5 months of osteogenesis. Among the 6 cases, 5 required the additional bone graft and 1 case only required the gingivoperioplasty. The newly formed bone tissues did not show any signs of bone resorption. However, a considerable degree of teeth displacement was shown. Conclusion: For the alveolar cleft too wide to be reconstructed by a general bone graft, it is strongly recommended to perform the reverse L osteotomy of the cleft side with Liou alveolar distraction device to initiate the alveolar osteogenesis. However, the migrated teeth showed some degree of relapse, thus, the orthodontic treatment is essential following the distraction osteogenesis treatment.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
• /
• pp.19-22
• /
• 2003

In this paper, a new small size Lateral Trench Electrode Power MOSFET with local doping is proposed. This new structure is based on the conventional lateral power MOSFET. The entire electrodes of proposed device are placed in trench oxide. The forward blocking voltage of the proposed device is improved by 3.3 times with that of the conventional lateral power MOSFET. The forward blocking voltage of proposed device is about 500V. At the same size, a increase of the forward blocking voltage of about 3.3 times relative to the conventional lateral power MOSFET is observed by using TMA-MEDICI which is used for analyzing device characteristics. Because the electrodes of the proposed device are formed in trench oxide respectively, the electric field in the device are crowded to trench oxide. And because of the structure which has a narrow drain doping width, the punch through breakdown can be occurred in higher voltage than that of conventional lateral power MOSFET. We observed that the characteristics of the proposed device was improved by using TMA-MEDICI and that the fabrication of the proposed device is possible by using TMA-TSUPREM4.

• 수산해양기술연구
• /
• 제41권4호
• /
• pp.241-247
• /
• 2005

The aim of this study was to develop a trawl escapement device which can improve the survival rate of young fishes passed through trawl codend. The sea experiments according to the bar space of the device and bar materials were carried out to decide the bar space and device materials in Korean southern sea and off Cheju island. Stainless pipes and MC bars were used to test the efficiency of escapement device materials. Although escapement rates of MC bar for main species were a little higher compare with stainless pipe, the efficiency of device for stainless pipe was better than MC bar. Escapement devices of sort-K type and grid panel type were also compared. Escapement rates of redlip croaker(Pseudosciaena polyactis), blackthroat seaperch(Doederleinia berycoides) and finespotted flounder (Pleuronichthys cornutus) showed 61.7%, 2.0% and 2.7% on the sort-x type and 69.9%, 1.1% and 2.0% for the grid panel type but the difference was little. Fishes under 20mm head width and fishes which swimming speed is so slow compared with body length could not go through well the device. Escapement rates according to the bar space were estimated using grid panel type. The rates of redlip croaker(Pseudosciaena polyactis) for the bar space of 20mm, 25mm, 35mm were increased as 60.3%, 61.0% and 77.8%, and 9.8%, 16.4% and 45.6% for horse mackere1(Trachurus japonicus), respectively.

• 마이크로전자및패키징학회지
• /
• 제29권2호
• /
• pp.99-105
• /
• 2022

칩사이즈가 작아짐에 따라 선폭 또한 미세화되면서 인터커넥션의 밀집정도가 증가하고 있다. 그로 인해 캐패시터 층과 전기전도층의 저항 차이로 인해 RC delay가 문제되고 있다. 이를 해결하기 위해서는 높은 전기전도도의 전극과 낮은 유전율의 유전체 개발이 요구된다. 본 연구에서는 PCB (Print Circuit Board)의 회로를 외부요인으로부터 보호하는 상용 PSR (photo solder resist)과 우수한 내열 및 저유전 특성을 보유한 PI (polyimide)를 혼합하여 저유전체 잉크 개발을 진행하였다. 그 결과 PSR과 PI를 10:3으로 혼합한 잉크가 가장 우수한 결과를 보였으며 20 GHz와 28 GHz에서 각각 유전 상수 약 2.6, 2.37을 보였고, 유전손실은 약 0.022, 0.016으로 측정되었다. 차후 어플리케이션 적용 가능성 검증을 위해 테프론에 제작된 다양한 선폭의 전송선로에 평가하였으며 그 결과, PSR만 사용했을 때보다 PI와 혼합한 저유전체 잉크를 사용한 전송선로의 손실이 S21에서 평균 0.12 dB 덜 감소한 결과를 보였다.

• 전기학회논문지
• /
• 제63권3호
• /
• pp.431-436
• /
• 2014

In this paper, temperature change properties on the 210kW-class Interior Permanent Magnet Synchronous Motor (IPMSM) are performed with the cooling performance of a water cooling device through the thermal characteristic analysis of the IPMSM considering a real driving pattern of urban railway vehicles. First, the thermal analysis modeling of 210kW-class IPMSM, which is an alternative to the conventional induction motor, and its water cooling device is conducted. Next, the thermal characteristic analysis of the IPMSM considering a real driving pattern of urban railway vehicles is performed using 2-Dimensional FEM tool. Finally, the calculated characteristic results are analyzed. Consequently, it is confirmed that the internal temperature of the 210kW-class IPMSM may be lowered to about 42~52% by maintaining the coolant flow rate of the water cooling device (Cross sectional shape of the pipe has 220mm width and 10mm height) for 0.2kg/s level.

• 한국전기전자재료학회논문지
• /
• 제15권9호
• /
• pp.758-763
• /
• 2002

A new small size Lateral Trench Electrode Insulated Gate Bipolar Transistor (LTEIGBT) is proposed and fabricated to improve the characteristics of device. The entire electrode of LTEIGBT is placed to trench type electrode. The LTEIGBT is designed so that the width of device is 19w. The latch-up current density of the proposed LTEIGBT is improved by 10 and 2 times with those of the conventional LIGBT and LTIGBT. The forward blocking voltage of the LTEIGBT is 130V. At the same size, those of conventional LIGBT and TIGBT are 60V and 100V, respectively. Because the electrodes of the proposed device is formed of trench type, the electric field in the device are crowded to trench oxide. When the gate voltage is applied 12V, the forward conduction currents of the proposed LTEIGBT and the conventional LIGBT are 80mA and 70mA, respectively, at the same breakdown voltage of 150V.

• Journal of Biosystems Engineering
• /
• 제29권6호
• /
• pp.487-494
• /
• 2004

This study was conducted to develope a fertilizer-soil incorporation band tiller for the walking cultivator. Because the mixing of soil and fertilizer in the furrow of dry-field has been done manually, several time, heavy labor and much man power were required for the job. This rotary type implement is developed to substitute this manual operation for soil-fertilizer incorporation. The results of this study are summarized as follows : 1) This implement was composed of tilling device, fertilizer application device, frame and tail wheel device. 2) The revolution of driving wheel was $11\~28\;rpm$, that of application roller was $13\~14\;rpm$ the application rate range per revolution of driving wheel was $4.43\~11.80\;g$g and the application rate range by the working speed and the opening quantity was $84.12\~557.20\;g/min$. 3) The adequate working speed was $0.20\~0.40\;m/s$ and the required minimum width of open furrow was 250 mm.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 추계학술대회 논문집
• /
• pp.414-417
• /
• 2001

Recently, developments of device using characteristics of ceramics as a new technical material is in progress. While doing so, Ultrasonic motor which is a part of research & flat-type $L_1-B_8$ mode Ultrasonic motor and measured the operation characteristics of its. The size of USM is 80*20*1.5[$mm{^1}$](length*width*thickness) and is constructed with stator by piezo-ceramics and stainless elastic body and rotator by bearings. As results of experiments, the fastest speed of revolution($\upsilon$), the maximum torque(T) and the efficiency($\eta$) were 37.5[cm/sec], 5.0[mN$\cdot$M] and 1.17[%] respectively when 27.9[kHz], 150[gf], 50[V] were applied. SO, we think this flat-type $L{_1}-B{_8}$ mode Ultrasonic motor is able to be used for applications in forwarding device of a paper or electric card so on. Key Words: Flat=type $L{_1}-B{_8}$ mode Ultrasonic Motors, Piezoelectric ceramics, forwarding device.

• 조명전기설비학회논문지
• /
• 제30권1호
• /
• pp.1-7
• /
• 2016

With a collimated $CO_2$ laser beam, the bidirectional current switching was realized in a two-terminal electronic device based on a highly resistive vanadium dioxide($VO_2$) thin film. A $VO_2$ thin film was grown on a $Al_2O_3$ substrate by a pulsed laser deposition method. For the fabrication of a two-terminal electronic device, the $VO_2$ thin film was etched by an ion beam-assisted milling method, and the $VO_2$ device, of which $VO_2$ patch width and electrode separation were 50 and $100{\mu}m$, respectively, was fabricated through a photolithographic method. A bias voltage range for stable bidirectional current switching was found by using the current-voltage property of the device measured in a current-controlled mode. The transient responses of bidirectionally switched currents were analyzed when the laser was modulated at a variety of pulse widths and repetition rates. A switching contrast was measured as ~3333, and rising and falling times were measured as ~39 and ~21ms, respectively.