• Title/Summary/Keyword: FAR25

Search Result 1,015, Processing Time 0.026 seconds

Effect of the far infrared irradiated water on the growth of the cotyledons, hypocotyls and roots of the spring radishes (원적외선 처리수가 봄 무의 자엽, 하배축, 뿌리 성장에 미치는 영향)

  • Cho, Bong-Heuy
    • Analytical Science and Technology
    • /
    • v.22 no.4
    • /
    • pp.277-284
    • /
    • 2009
  • The germination rate of radishes grown with the far infrared irradiated water and drinking water was 100% and 78% respectively. The far infrared irradiated water stimulated the cell division of the cotyledons and enlarged the cell sizes both in the dark and in the light. In the dark and light conditions, the size of the cotyledons of transversal axis and longitudinal axis grown with the far infrared irradiated water was bigger than that grown with the drinking water. The content of chlorophyll and the consumption of $CO_2$ of the cotyledons grown with the far infrared irradiated water were higher, respectively. Osmotic pressure of the cotyledons grown with the far infrared irradiated water was 1.25 factors higher than that grown with the drinking water. The water potential of the cotyledons grown with the far infrared irradiated water was more negative value. The length of hypocotyls grown with the far infrared irradiated water was 2.18 factors longer in the dark, 1.99 factors longer in the light than that grown with the drinking water and the radish roots grown with the far infrared irradiated water were larger, respectively.

High Voltage IGBT Improvement of Electrical Characteristics (고내압 IGBT의 전기적 특성 향상에 관한 연구)

  • Ahn, Byoung-Sup;Chung, Hun-Suk;Jung, Eun-Sik;Kim, Seong-Jong;Kang, Ey-Goo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.25 no.3
    • /
    • pp.187-192
    • /
    • 2012
  • Development of new efficient, high voltage switching devices with wide safe operating area and low on-state losses has received considerable attention in recent years. One of those structures with a very effective geometrical design is the trench gate Insulated Gate Bipolar Transistor(IGBT).power IGBT devices are optimized for high-voltage low-power design, decided to aim. Class 1,200 V NPT Planer IGBT, 1,200 V NPT Trench IGBT for class has been studied.

A Study on Electrical Characteristics Improvement on Field Stop IGBT Using Trench Gate Structure (Trench Gate를 이용한 Field Stop IGBT의 전기적 특성 분석에 관한 연구)

  • Nam, Tae-Jin;Jung, Eun-Sik;Chung, Hun-Suk;Kang, Ey-Goo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.25 no.4
    • /
    • pp.266-269
    • /
    • 2012
  • The most recently IGBT (insulated gate bipolar mode transistor) devices are in the most current conduction capable devices and designed to the big switching power device. Use this number of the devices are need to high voltage and low on-state voltage drop. And then in this paper design of field stop IGBT is insert N buffer layer structure in NPT planar IGBT and optimization design of field stop IGBT and trench field stop IGBT, both devices have a comparative analysis and reflection of the electrical characteristics. As a simulation result, trench field stop IGBT is electrical characteristics better than field stop IGBT.

An Analysis on the Reduction of Measurement Time Using Interpolation Algorithm in Near-field RCS Measurements for Aircraft Shape (항공기 형상에 대한 근전계 RCS 측정에서 내삽 알고리즘을 이용한 측정시간 단축에 대한 분석)

  • Park, Homin
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.25 no.4
    • /
    • pp.339-346
    • /
    • 2022
  • The importance of stealth technology is increasing in modern warfare, and Radar Cross Section(RCS) is widely used as an indicator of stealth technology. It is useful to measure RCS using an image-based near-field to far-field transformation algorithm in short-range monostatic conditions. However, the near-field measurement system requires a longer measurement time compared to other methods. In this work, it is proposed to reduce the measured data using an interpolation method in azimuth angular domain. The calculated far-field RCS values according to the sampling rate is shown, and the performance of the algorithm applied with interpolation in the angular domain is presented. It is shown that measurement samples can be reduced several times by using the redundancy in the angular domain while producing results similar to the conventional method.

The Change of the Structure of Green Space by the Change of the Floor Area Ratio in Apartment Complex (용적률 변화에 따른 공동주택 단지내 녹지구조 변화특성)

  • 김정호;이경재;김정호
    • Korean Journal of Environment and Ecology
    • /
    • v.18 no.1
    • /
    • pp.42-52
    • /
    • 2004
  • The purpose of this study was to propose the change of green area and green structure according to the change of the Floor Area Ratio(FAR) of apartment complex. The survey site was selected two each of apartment complex after due consider three type that is, the FAR below 100%, the FAR below 250% and the FAR over 250%. Green rate is 40.23~44.23%, green width is 3~15m, green volume is 1.06~1.71㎥/$m^2$, planting density of cannopy layer is 0.04~0.06tree/$m^2$, planting density of understory layer is 0.06~0.20tree/$m^2$ in case of Hwagok 2nd Jugong apartment(FAR 99%) and Gaepo Jugong apartment(FAR 73%) constructed in the 1970~1980. Green rate is 24.16~26.16%, green width is 3~7m, green volume is 0.84~1.54㎥/$m^2$, planting density of cannopy layer is 0.18~0.31tree/$m^2$, planting density of understory layer is 0.15~0.35tree/$m^2$ in case of Deungchon Jugong aparment(FAR 226%) and Gaehwa apartment(FAR240%) construsted in the mid-1990's. Green rate is 23.47~25.53%, green width is 2~6m, green volume is 1.06~2.12㎥/$m^2$, planting density of cannopy layer is 0.25tree/$m^2$, planting density of understory layer is 0.22~0.37tree/$m^2$ in case of Hanbo Guam apartment(FAR 269%) and Donga 3rd apartment(FAR 376%) constructed in the last-1990's. As the results of analysis of green structure according to changes of the Floor Area Ratio(FAR), the greater the FAR, the higher the rate of green area. The green volume and planted density is low without the change of the FAR and planted structure was simple-layer structure composed of alien woody species.

A Study on High-voltage Low-power Power MOSFET of Optimization for Industrial Motor Drive (산업용 모터 구동을 위한 고내압 저전력 Power MOSFET 최적화 설계에 관한 연구)

  • Kim, Bum-June;Chung, Hun-Suk;Kim, Seong-Jong;Jung, Eun-Sik;Kang, Ey-Goo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.25 no.3
    • /
    • pp.170-175
    • /
    • 2012
  • Power MOSFET is develop in power savings, high efficiency, small size, high reliability, fast switching, low noise. Power MOSFET can be used high-speed switching transistors devices. Recently attention to the motor and the application of various technologies. Power MOSFET is devices the voltage-driven approach switching devices are design to handle on large power, power supplies, converters, motor controllers. In this paper, design the 600 V Planar type, and design the trench type for realization of low on-resistance. For both structures, by comparing and analyzing the results of the simulation and characterization.

A Study on the Field Ring of High Voltage Characteristics Improve for the Power Semiconductor (전력반도체 고내압 특성 향상을 위한 필드링 최적화 연구)

  • Nam, Tae-Jin;Jung, Eun-Sik;Jung, Hun-Suk;Kim, Sung-Jong;Kang, Ey-Goo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.25 no.3
    • /
    • pp.165-169
    • /
    • 2012
  • Power semiconductor devices are widely used as high voltage applications to inverters and motor drivers, etc. The blocking voltage is one of the most important parameters for power semiconductor devices. And cause of junction curvature effects, the breakdown voltage of the device edge and device unit cells was found to be lower than the 'ideal' breakdown voltage limited by the semi-infinite junction profile. In this paper, Propose the methods for field ring design by DOE (Design of Experimentation). So The field ring can be improve for breakdown voltage and optimization.