• Proceedings of the KIPE Conference
• /
• 2019.11a
• /
• pp.13-15
• /
• 2019

듀얼 인버터를 가진 개방 권선형 영구자석 동기 전동기는 같은 DC Link 전압으로 모터에 더 큰 전압을 사용할 수 있게 할 수 있다. 이 때문에 DC Link와 인버터 사이의 DC/DC Boost 컨버터의 필요성을 없애줄 뿐 아니라 배터리의 전압을 낮출 수 있어 안전상의 이점 및 BMS의 요구 조건을 낮추므로 경제적 이점을 가질 수 있다. 이 시스템은 경제적 이점 외에도 모터에 고전압을 인가함으로써 기존에 비해 고속 운전 영역 확장 또는 운전 영역을 기존과 동일하게 유지한다면 인버터의 손실 감소라는 이점 또한 얻을 수 있다. 그러나 1차단 인버터와 2차단 인버터의 합성전압 차이로 인해 생기는 Zero Sequence Voltage (ZSV)로 인해 시스템의 손실을 증대시키는 Zero Sequence Current (ZSC)가 흐를 수 있다. 본 연구에서는 이를 억제하기 위한 스위칭 패턴 형성을 위한 PWM 캐리어 생성 방법에 대해 제시하고, 이 방법을 적용하여 스위칭 순서 상 센터 영벡터의 유/무에 따른 제어 영향성 분석을 추가로 진행하여 전류 리플을 줄일 수 있는 스위칭 패턴 생성 방법을 제시한다.

• ETRI Journal
• /
• v.36 no.6
• /
• pp.924-930
• /
• 2014

This paper presents a $0.13{\mu}m$ CMOS 3-level envelope delta-sigma modulation (EDSM) RF signal generator, which synthesizes a 2.6 GHz-centered fully symmetrical 3-level EDSM signal for high-efficiency power amplifier architectures. It consists of an I-Q phase modulator, a Class B wideband buffer, an up-conversion mixer, a D2S, and a Class AB wideband drive amplifier. To preserve fast phase transition in the 3-state envelope level, the wideband buffer has an RLC load and the driver amplifier uses a second-order BPF as its load to provide enough bandwidth. To achieve an accurate 3-state envelope level in the up-mixer output, the LO bias level is optimized. The I-Q phase modulator adopts a modified quadrature passive mixer topology and mitigates the I-Q crosstalk problem using a 50% duty cycle in LO clocks. The fabricated chip provides an average output power of -1.5 dBm and an error vector magnitude (EVM) of 3.89% for 3GPP LTE 64 QAM input signals with a channel bandwidth of 10/20 MHz, as well as consuming 60 mW for both channels from a 1.2 V/2.5 V supply voltage.

• Molecules and Cells
• /
• v.27 no.2
• /
• pp.237-241
• /
• 2009

Pathogens Burkholderia pseudomallei (Bp) and Burkholderia mallei (Bm) contain a large number (> 12,000) of Simple Sequence Repeats (SSRs). To study the extent to which these features have contributed to the diversification of genes, we have conducted comparative studies with nineteen genomes of these bacteria. We found 210 genes with characteristic types of SSR variations. SSRs with nonamer repeat units were the most abundant, followed by hexamers and trimers. Amino acids with smaller and nonpolar R-groups are preferred to be encoded by the variant SSRs, perhaps due to their minimal impacts to protein functionality. A majority of these genes appears to code for surface or secreted proteins that may directly interact with the host factors during pathogenesis or other environmental factors. There also are others that encode diverse functions in the cytoplasm, and this protein variability may reflect an extensive involvement of phase variation in survival and adaptation of these pathogens.

• Journal of electromagnetic engineering and science
• /
• v.6 no.1
• /
• pp.30-35
• /
• 2006

This paper describes fully integrated low phase noise MMIC voltage controlled oscillators(VCOs). The Asymmetrical Inductance Tank VCO(AIT-VCO), which optimize the shortcoming of the previous tank's inductance optimization approach, has lower phase noise performance due to achieving higher equivalent parallel resistance and Q value of the tank. This VCO features an output power signal in the range of - 11.53 dBm and a tuning range of 261 MHz or 15.2 % of its operating frequency. This VCO exhibits a phase noise of - 117.3 dBc/Hz at a frequency offset of 100 kHz from carrier. A phase noise reduction of 15 dB was achieved relative to only one spiral inductor. The AIT-VCO achieved low very low figure of merit of -184.6 dBc/Hz. The die area, including buffers and bond pads, is $0.9{\times}0.9mm^2$.

• Proceedings of the KIEE Conference
• /
• 2006.07c
• /
• pp.1359-1360
• /
• 2006

lTO(Indium-Tin-Oxide) was used as anode material for OLED. Characteristics of ITO have great effect on efficiency of OLEDS(Organic light emitting diodes). ITO surface was treated by Nd:YAG laser in order to improve its chemical properties, wettability, adhesive property and to remove the surface contaminants while maintaining its original function. In this study, main purpose was to improve the efficiency of OLEDs by the ITO surface treatment: ITO surface was treated using a Nd:YAG(${\lambda}=266nm$, pulse) with a fixed power of 0.06[w] and various stage scanning velocities. Surface morphology of the ITO was investigated by AFM. Test OLEDs with surface treated ITO were fabricated by deposition of TPD (HTL), Ald3 (ETL/TML) and Al (cathode) thin films. Device performance of the OLEDs such as V-I-L was investigated using Source Measurement Unit (SMU: Keithly. Model 2400) and Luminance Measurement (TOPCON. BM-8).

• International Journal of Industrial Entomology and Biomaterials
• /
• v.12 no.1
• /
• pp.7-14
• /
• 2006

Silkworm diseases are better prevented than cured. Disinfection and hygiene are the two important aspects in silkworm rearing to prevent the diseases. Suitable disinfectant is the primary need to disinfect the rearing house, its surroundings and appliances to eliminate the persistent pathogens from the rearing environment. In this direction, Serichlor, a new disinfectant in Indian Sericulture marketed as Serichlor-60 (contains 60,000 ppm of chlorine dioxide) and Serichlor-20 (contains 20,000 ppm of chlorine dioxide) has been evaluated for its germicidal effect against the pathogens of silkworm, viz., spores of Nosema bombycis, Bacillus thuringiensis, polyhedra of BmNPV and conidia of Beauveria bassiana both in vitro and in vivo. Results indicated that high concentration (2,500 ppm of chlorine dioxide) is required to kill all the pathogens at 100% level. The efficacy of the Serichlor was greatly enhanced by the addition of 0.5% slaked lime solution. 500 ppm of chlorine dioxide in 0.5% slaked lime solution was found effective against all the pathogens tested. This concentration of disinfectant was also found effective for disinfection of rearing house, rearing appliances and silkworm egg surface. The disinfectant is stable, non hazardous, least corrosive and most suitable for Indian Sericulture.

• Journal of Fashion Business
• /
• v.13 no.4
• /
• pp.37-50
• /
• 2009

Recently, as individual 3D avatars are rapidly generalized in internet sites, its commercial applications for fashion business are being tried in ubiquitous fashion shopping era. In this research, we have investigated and analyzed patent problems of 3D avatar including personal body data to activate the fashion business using 3D avatars. Here, considering the patents for 3D face and body generation methods are already published, this research is focused on whole 3D body avatar obtained from individual body information. Firstly, definition of 3D avatar and its application cases have been investigated and then it has been researched whether or not legal protections by patent law, copyright law, computer program protection law, design protection law and fair competition laws are feasible in view of the subjects to be protected in each law and requirements for such protections. It was revealed that patent law may provide legal protections for 3D avatar and domestic and foreign patents related to 3D avatar have been researched.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.12
• /
• pp.2205-2209
• /
• 2007

In this paper, a voltage controlled oscillator(VCO) of core components for wireless subscriber network is designed. The type of oscillator is colpits method and the oscillator device uses a LC resonator. The product is made on FR-4 substrate with dielectric constant of 4.6. The designed VCO is operated at 3.2V, 10mA and has output value of 0.67dB. The VCO's phase noise property is -102DBc/Hz at offset frequence of 100kHz. The fabricated VCO is the same as target value and can be used for wireless subscriber network.

• Journal of IKEEE
• /
• v.23 no.1
• /
• pp.181-187
• /
• 2019

In this paper, we demonstrated a power amplifier monolithic microwave integrated circuit (MMIC) for X-band radar applications. It utilizes commercial $0.25{\mu}m$ GaN-based high electron mobility transistor (HEMT) technology and delivers more than 20 W of output power. The developed GaN-based power amplifier MMIC has small signal gain of over 22 dB and saturated output power of over 43.3 dBm (21.38 W) in a pulse operation mode with pulse width of $200{\mu}s$ and duty cycle of 4% over the entire band of 9 to 10 GHz. The chip dimensions are $3.5mm{\times}2.3mm$, generating the output power density of $2.71W/mm^2$. Its power added efficiency (PAE) is 42.6-50.7% in the frequency bandwidth from 9 to 10 GHz. The developed GaN-based power amplifier MMIC is expected to be applied in a variety of X-band radar applications.

• Journal of IKEEE
• /
• v.24 no.4
• /
• pp.1129-1135
• /
• 2020

The effects of battery aging limit the rechargeable capacity, State of Health(SoH). It is very important to estimate the SoH in the battery monitoring system(BMS) and many algorithms of measuring the internal resistance of the battery were proposed. A method is used by applying a current source of a specific frequency to the battery and measuring the voltage response. When charging harmonic noise is generated in the voltage response, it results in poor resistance measurement accuracy. In this paper, a robust battery internal resistance measurement algorithm is proposed to eliminate the effect of charging noise by integrating the current source and voltage response signals for a certain period. It showed excellent accuracy and stable measurement results. Applying to the BMS for uninterruptible power supply, the usefulness of the proposed method is verified.