• The KSFM Journal of Fluid Machinery
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• v.20 no.1
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• pp.59-64
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• 2017

Diverter is an essential element in gravimetric calibration method of flowmeter. Error of diverter are influenced by flow velocity profile of nozzle outlet, motion velocity of diverter and detecting location. That's why, time detection position of diverter is tuned through repetitive test for minimizing error of diverter. Further the diverter must be compared with the other institutions test since the influence on the accuracy of the flow meter used in the test. In this paper, errors (flow velocity profile of nozzle outlet, motion velocity of diverter and detecting location) of diverter are decreased by produced uni-direction diverter and error of gravimetric calibration system is decreased. Uni-direction diverter is calibrated by gravimetric calibration system with precision flowmeter, the flowmeter is calibrated by pipe prover and other institutions and uni-direction diverter is evaluated. Uni-direction diverter is not influenced by flow velocity profile of nozzle outlet, motion velocity of diverter and detecting location. As a result, Uni-direction diverter can calibrate in wider scope since increasing ratio of maximum and minimum flow rate of uni-direction diverter.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.623-629
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• 2020

This study examined the airflow field around a gun port on the flight condition of gunfire to verify the aircraft performance and safety effects and gun gas rate, path according to the options of diverter configuration. The gun port diverter not only effectively lowered the heat generated by gunfire but also effectively discharged the gun gas upwards. The path of gun gas can be changed according to its configuration. According to the optional configuration of the rear-gun-port diverter, the flow rate, path, and pressure of the gun gas were analyzed during gunfire. An analysis of the internal velocity distribution and the temperature change of the gun port revealed a rapid decrease in flow rate through the rear diverter according to the option configuration. The forward flow rate showed a similar tendency with little change. This ensures that the gun gas generated during gunfire has a sufficient flow distance from the aircraft surface, regardless of the rear gun port diverter's optional configuration. The flow stagnation of gun gas according to the option configuration of diverter had a great influence on the internal temperature rise of a gun port.

• The KSFM Journal of Fluid Machinery
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• v.11 no.3
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• pp.50-55
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• 2008

The diverter system is a key component in achieving a high accuracy liquid flow rate standard using a static gravimetric system with a flying start and stop method. The diverter is a moving device used to direct flow alternately along its normal course(by pass) or towards the weighing tank. The time needed for collection into the weighing tank is measured using a timer. So it is important to the diversion period is sufficiently fast and triggering point of timer which is determined the filling time. On this studies show that uncertainty of diverter system for changing diversion speed and triggering point was estimated in accordance with Guide to The Expression of Uncertainty in Measurement(ISO).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.342-345
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• 2002

A new lateral trench electrode IGBT with p+ diverter was Proposed to suppress latch-up of LTIGBT. The p+ diverter was placed between the anode and cathode electrode. The latch-up of LTEIGBT with a p+ diverter was effectively suppressed to sustain an anode voltage of 8.7V and a current density of 1453A/$\textrm{cm}^2$ while in the conventional LTIGBT, latch-up occurred at an anode current density of 540A/$\textrm{cm}^2$. And the forward blocking voltage of the proposed LTEIGBT with a p+ diverter was about 140V. That of the conventional LTIGBT of the same size was no more than 105V. When the gate voltage is applied 12V, the forward conduction currents of the Proposed LTEIGBT with a p+ diverter and the conventional LIGBT are 90mA and 70mA, respectively, at the same breakdown voltage of 150V.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.7
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• pp.546-550
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• 2001

A new Lateral Trench Insulated Gate Bipolar Transistor(LTIGBT) with p$^{+}$ diverter was proposed to improve the characteristics of the conventional LTIGBT. The forward blocking voltage of the proposed LTIGBT with p$^{+}$ diverter was about 140V. That of the conventional LTIGBT of the same size was 105V. Because the p$^{+}$ diverter region of the proposed device was enclosed trench oxide layer, he electric field moved toward trench-oxide layer, and punch through breakdown of LTIGBT with p$^{+}$ diverter was occurred, lately. Therefore, the p$^{+}$ diverter of the proposed LTIGBT didn't relate to breakdown voltage in a different way the conventional LTIGBT. The Latch-up current densities of the conventional LTIGBT and proposed LTIGBT were 540A/$\textrm{cm}^2$, and 1453A/$\textrm{cm}^2$, respectively. The enhanced latch-up capability of the proposed LTIGBT was obtained through holes in the current directly reaching the cathode via the p$^{+}$ divert region and p$^{+}$ cathode layer beneath n$^{+}$ cathode layer./ cathode layer.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.9
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• pp.750-757
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• 2002

A new lateral trench LTEIGBT with p+ diverter was proposed to suppress latch-up of LTIGBT The p+ diverter was placed between the anode and cathode electrode. The latch-up of LTEICBT with a p+ diverter was effectively suppressed to sustain an anode voltage of 8.7V and a current density of 1453A/$\textrm{cm}^2$ while in the conventional LTIGBT, latch-up occured at an anode current density of 540A/$\textrm{cm}^2$. In addition, the forward blocking voltage of the proposed LTEIGBT with a p+ diverter was about 140V. The forward blocking voltage of the conventional LTIGBT of the same size was no more than 105V, We fabricated the proposed LTEIGBT with a p+ diverter after the device and process simulation was finished. When the gate voltage is applied 12V, the forward conduction currents of the proposed LTEIGBT with a p+ diverter and the conventional LIGBT are 90㎃ and 70㎃, respectively, at the same breakdown voltage of 150V.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1042-1046
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• 2008

Both the weighing bridge and the diverter system is a important component in achieving a high accuracy liquid flow rate standard using a static gravimetric method. The weighing bridge is a tank which weighing collected flow with a load cells. The diverter is a moving device used to direct flow alternately along its normal course(by pass) or towards the weighing tank. The time needed for collection into the weighing tank is measured using a timer. So it is important to the diversion period is sufficiently fast and triggering point of timer which is determined the filling time. On this studies show that the measurement deviation of load cell and uncertainty of diverter system for changing diversion speed and triggering point was estimated in accordance with Guide to The Expression of Uncertainty in Measurement(ISO).

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1315-1316
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• 2007

This is paper, a new structure to effectively improve the Vce(sat) voltage and latch-up current in NPT type IGBTs with hole barrier layer and diverter. The hole barrier layer acts as a barrier to prevent the holes from flowing into the p-layer and stores them in the n-layer. And the diverter significantly reduce hole current from flowing into the p-layer and improve latch up current. Analysis on the Breakdown voltage shows identical values compared to existing Conventional IGBT structures. This shows an improvement on Vce(sat) and Latct-up current without lowering other characteristics of the device. The electrical characteristics were studied by MEDICI simulation results.

• Nuclear Engineering and Technology
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• v.29 no.4
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• pp.348-359
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• 1997

This paper reviews cooling aspects of the diverter system in Tokamak fusion devices with primary emphasis on the critical heat flux (CHF) issues for oater-cooled designs. General characteristics of four (4) coolant options for diverter cooling gases, oater, liquid metal, and organic liquid - are discussed first, focusing on the comparison of advantages and disadvantages of those options. Then results of recent studies on the high-heat-flux CHF of water at subcooled high-velocity conditions are reviewed to provide a general idea on the feasibility of the water-cooled diverter concept for future Tokamak fusion reactors. Water is assessed to be the most viable and practical coolant option for diverters of future experimental Tokamaks.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.511-511
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• 2001