• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.2
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• pp.89-95
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• 2003

We consider a problem of application of analytical redundancy to engine synchronization process of spark ignition engines, which is critical to timing for every ECU process including ignition and injection. The engine synchronization process we consider here is performed using the pulse signal obtained by the revolution of crankshaft trigger wheel (CTW) coupled to crank shaft. We propose a discrete-time linear model for the signal, for which we construct FDI (Fault Detection & Isolation) system consisting residual generator and threshold based on linear observer.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.9
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• pp.36-43
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• 2010

This paper proposes a new type of voltage sag-swell compensator based on a Z-source AC-AC converter. The proposed topology employs a pulse width modulation (PWM) Z-source AC-AC converter along with a injection transformer. A safe commutation strategy is used to eliminate voltage spikes on switches without snubber circuit. During a voltage sag or swell, the proposed system controls the adding or missing voltage and maintains the rated voltage of sinusoidal waveform at the terminals of the critical loads. The proposed system is able to compensate 20[%] voltage swell and is also able to compensate 60[%] voltage sag. In order to control and detect the voltage sag and swell, the peak voltage detection method is applied. Also, the operating principles of the proposed system are described, and a circuit analysis is provided. Finally, PSIM simulation and experimental results are presented to verify the proposed concept and theoretical analysis.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05a
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• pp.153-156
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• 2005

In this study, we have investigated transient properties of top emission organic light emitting diode (OLED) with a red electrophosphorescent dopant. The emission spectrum shows a strong peak at 620 nm accompanied with a small peak at 675 nm in the red region. Time evolution of electrophosphorescence reveals a decay time of 703 ms at a voltage pulse of 5 V in a device with an emitting area of 20 $mm^2$. Rise and delay times vary from 450 to 14 ms and 73 to 3 ms, respectively, as the voltage amplitude increases from 4.5 to 10 V. These results are compared with the red emitting device without an electron injection layer.

• Journal of Power Electronics
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• v.19 no.2
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• pp.560-568
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• 2019

This paper studies the inherent relationship between currents and zero-sequence components. Then a precise algorithm is proposed to calculate the injected zero-sequence component to control the DC-Link neutral-point voltage balance, which can result in a more efficient and flexible neutral point voltage balance with a desirable performance. In addition, it is shown that carried-based PWM with the calculated zero-sequence component scheme can be equivalent to space-vector pulse-width modulation (SVPWM). Based on the proposed method, the optimal zero-sequence component of the feasible modulation indices is analyzed. In addition, the unbalanced load limitation of the DC-Link neutral-point voltage balance control is also revealed. Simulation and experimental results are shown to verify the validity and practicality of the proposed algorithm.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.133-133
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• 2003

Recently, sperm has been used as a vector to carry exogenous genes for the production of transgenic animals. However, the success in cattle is low, due to deficiencies in oocyte activation and sperm decondensation caused by high disulphide bond (S=S) content in mature sperm. This study was carried out to develop an effective method for producing transgenic animals with round spermatids (RS). Two methods of embryo production - electric fusion (EC) or intracyto-plasmic injection (IC) and three activation treatments were compared. RS were isolated from bull testes by Percoll density gradients (20, 35, 40, 45 and 90%). Fusion between ooplast and RS was performed with a single DC electric pulse (1.0 KV/cm, 45 sec) in 0.28 M mannitol solution supplemented with 100 M CaCl2 and 100 M MgCl$_2$. (중략)

• Journal of IKEEE
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• v.24 no.1
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• pp.161-169
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• 2020

In order to reduce the manufacturing cost of MCU chips used in applications such as wireless chargers and USB-C, compared to DP-EEPROM (Double Poly EEPROM), which requires 3 to 5 additional process masks, it is even more necessary MTP(Multi-Time Programmable), which is less than one additional mask and have smaller unit cell size. In addition, in order to improve endurance characteristics and data retention characteristics of the MTP memory cell due to E/P(Erase / Program) cycling, the distribution of the V_TP(Program Threshold Voltage) and the V_TE(Erase Threshold Voltage) needs to be narrow. In this paper, we proposed a current-type BL S/A(Bit-Line Sense Amplifier) circuit, WM(Write Mask) circuit, BLD(BL Driver) circuit and a algorithm, which can reduce the distribution of program and V_T and erase V_T, through compare the target current by performing the erase and program pulse of the short pulse several times, and if the current specification is satisfied, the program or erase operation is no longer performed. It was confirmed that the 256Kb MTP memory fabricated in the Magnachip semiconductor 0.13㎛ process operates well on the wafer in accordance with the operation mode.

• Journal of Embryo Transfer
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• v.17 no.1
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• pp.45-53
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• 2002

The main goal of this study was to produce transgenic porcine embryos by direct injection of sperm-mediated exogenous DNA. Spermatozoa (6$\times$10$^{6}$ sperms of final concentration) were mixed with pcDNA LAC Z (20 ng/$\mu$l) and subjected into electroporation (300~750 volts, 25 $\mu$F, 0.4 cm electrode). After sperm injection, the oocytes were activated electrically (1.7 KV/cm, 30$\mu$sec, single pulse) in 0.3 M mannitol solution or not. The sperm injected eggs were cultured in NCSU 23 medium (0.4% BSA) at 39$^{\circ}C$, 5% $CO_2$ in air fur 144 h. The rates of cleavage and development into blastocyst stage in activation group were significantly higher than those of non-activation group (79.6% and 24.1% vs. 46.3% and 14.4%, respectively, p<0.05). Control oocytes and shame injection were developed to blastocysts low (2.5%). Sixty five (27.1%) out of 240 embryos observed in activation and non-activation groups were showed positive by X-gal staining. However, all embryos in both groups were expressed partial or mosaic pattern. These results suggested that electrical stimulation far oocytes activation after sperm injection enhances the incidence of both fertilization and development fellowing sperm injection in the pig. Our study also suggested that sperm-mediated transfer of exogenous DNA by ICSI would be used as a valuable tool for the production of transgenic porcine embryos.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.61-61
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• 2001

The main goal of this study was to produce transgenic piglets by the method of injection of sperm-mediated exogenous DNA. Spermatozoa (1$\times$106 sperm of final concentration) obtained from caudal epididymis were mixed with pBC1-hEPO (20 ng/${mu}ell$) or pcDNA3 LAC Z (20 ng/${mu}ell$), and followed by electroporation (500 V, 25 ㎌). Matured oocytes having the first polar body and dense cytoplasm were selected and centrifuged at 12,000g for 6 min. After sperm injection, the oocytes were activated electrically (1.7 ㎸/cm, 30 $\mu$ sec, single pulse) in 0.3 M mannitol solution. Eggs injected sperm were cultured in NCSU 23 medium (0.4% BSA) at 39$^{\circ}C$, 5% $CO_2$ in air for 192 h. This study were comprised 3 experiments. Experiment 1 compared the developmental efficiencies between the sperm-injected oocytes (Group 1) and further activated electrically (Group 2). Experiment 2 compared the expression of pcDNA3 LAC Z in the embryos produced by Group 1 and Group 2. Finally, experiment 3 carried out transfer of embryos (1-8 cell stage) transfected with pBC1 -hEPO into surrogate recipients synchronized by injection of combination of PG600 with hCG. The rates of cleavage and development into blastocyst stage in Group 2 were significantly higher than those of Group 1 (71.3% and 28.1% vs. 43.3% and 10.3%, respectively, p<0.05). Thirty (24.2%) out of 124 embryos analyzed in Group 2 were positive by X-gal. Similarly, in Group 1, 16.3% (8/49) were positive. After transfer of 789 embryos to 7 recipient gilts, three out of them examined by ultrasound became pregnant. One recipient is in day 50 pregnancy. On day 54 of gestation, two were carried out uterotomy in order to confirm the pregnancy One had 7 and another had 2 fetuses. We conclude that injection of sperm-mediated gene transfer will be used as a valuable tool for the production of transgenic piglets.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.8
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• pp.772-780
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• 2013

The high-altitude electromagnetic pulse(HEMP) conducted environment and the HEMP radiated environment are established as the consequences of a high-altitude nuclear explosion. The IEC 61000-2-10, the international standard, defines the HEMP conducted environment. The IEC 61000-5-5 defines how protective devices for conducted disturbance proposed for HEMP protection shall be specified. The IEC 61000-4-24 deals with methods for testing protective devices for HEMP conducted disturbance. The IEC 61000-4-24:1997 mainly describes the measurement method of small protective components. However, it does not provide the measurement method for a combination filter of a protective component and a filter which is widely used in recent. It is important to consider the characteristic of the measurement setup parameters like thickness and length of the cable and its height above ground plane etc. in establishing measurement setup because HEMP conducted disturbances include the frequency spectrum below 50 MHz. This paper deals with the optimized measurement method, considering the frequency spectrum of HEMP conducted disturbance, current waveform, and analyzing the effects of cables existing in the measurement setup.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.3
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• pp.430-436
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• 2008

Recently, there are many cases to use a ship's engine performance analyzer(SEPA) to measure pressure in cylinder and top dead center(TDC) of piston of engine, and analyze its performance such as fuel injection time and horsepower as well as wear of piston ring. But, SEPA needs TDC pulses($T(1){\sim}T(n)$) generated when pistons of engine are located to the TDC position ($TDC(1){\sim}TDC(n)$), these pulses are gathered from sensors connected to gear wheel of the propeller shaft in the remote distance from the measurement point. Therefore, operators need a long wire cable(WRC) to TDC detecting sensor to get these pulses, but this method is a very uncomfortable and expensive in case of installation, and it might decrease user's purchase desire. In this paper, we design and fabricate a small and inexpensive MODEM cable(M0C) so that it may be available to transmit TDC pulse generated from sensor in propeller shaft through existing power line. We also verify the facts that this MOC can be applied to SEPA and the effectiveness of the system through the experiments.