• Title/Summary/Keyword: Lee Jang Ga

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Improvement of the LED Performance Using Mg Delta-doing in p Type Cladding Layer for Sensor Application (p 형 반도체 층의 Mg 델타 도핑을 이용한 센서 광원 용 LED의 성능 향상)

  • Kim, Yukyung;Lee, Seungseop;Jeon, Juho;Kim, Mankyung;Jang, Soohwan
    • Journal of Sensor Science and Technology
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    • v.31 no.1
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    • pp.31-35
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    • 2022
  • The efficacy improvement of the light emitting diode (LED) was studied for the realization of small-size, low power consumption, and highly sensitive bio-sensor instrument. The performance of the LED with Mg delta-doping at the interface of AlGaN/GaN super-lattice in p type cladding layer was simulated. The device with Mg delta-doping showed improved current, radiative recombination rate, electroluminescence, and light output power compared to the conventional LED structure. Under the bias condition of 5 V, the improved device exhibited 20.8% increase in the light output power. This is attributed to the increment of hole concentration from stable ionization of Mg in p type cladding layer. This result is expected to be used for the miniaturization, power saving, and sensitivity improvement of the bio-sensor system.

Comparative Study of Artificial-Intelligence-based Methods to Track the Global Maximum Power Point of a Photovoltaic Generation System (태양광 발전 시스템의 전역 최대 발전전력 추종을 위한 인공지능 기반 기법 비교 연구)

  • Lee, Chaeeun;Jang, Yohan;Choung, Seunghoon;Bae, Sungwoo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.27 no.4
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    • pp.297-304
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    • 2022
  • This study compares the performance of artificial intelligence (AI)-based maximum power point tracking (MPPT) methods under partial shading conditions in a photovoltaic generation system. Although many studies on AI-based MPPT have been conducted, few studies comparing the tracking performance of various AI-based global MPPT methods seem to exist in the literature. Therefore, this study compares four representative AI-based global MPPT methods including fuzzy logic control (FLC), particle swarm optimization (PSO), grey wolf optimization (GWO), and genetic algorithm (GA). Each method is theoretically analyzed in detail and compared through simulation studies with MATLAB/Simulink under the same conditions. Based on the results of performance comparison, PSO, GWO, and GA successfully tracked the global maximum power point. In particular, the tracking speed of GA was the fastest among the investigated methods under the given conditions.

InGaAs-based Tunneling Field-effect Transistor with Stacked Dual-metal Gate with PNPN Structure for High Performance

  • Kwon, Ra Hee;Lee, Sang Hyuk;Yoon, Young Jun;Seo, Jae Hwa;Jang, Young In;Cho, Min Su;Kim, Bo Gyeong;Lee, Jung-Hee;Kang, In Man
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.17 no.2
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    • pp.230-238
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    • 2017
  • We have proposed an InGaAs-based gate-all-around (GAA) tunneling field-effect transistor (TFET) with a stacked dual-metal gate (DMG). The electrical performances of the proposed TFET are evaluated through technology computer-aided design (TCAD) simulations. The simulation results show that the proposed TFET demonstrates improved DC performances including high on-state current ($I_{on}$) and steep subthreshold swing (S), in comparison with a single-metal gate (SMG) TFET with higher gate metal workfunction, as it has a thinner source-channel tunneling barrier width by low workfunction of source-side channel gate. The effects of the gate workfunction on $I_{on}$, the off-state current ($I_{off}$), and S in the DMG-TFETs are examined. The DMG-TFETs with PNPN structure demonstrate outstanding DC performances and RF characteristics with a higher n-type doping concentration in the $In_{0.8}Ga_{0.2}As$ source-side channel region.

Compositions and Contents Anthocyanins in Blueberry (Vaccinium corymbosum L.) Varieties (블루베리(Vaccinium corymbosum L.) 품종별 안토시아닌 조성 및 함량)

  • Lee, Min-Ki;Kim, Heon-Woong;Lee, Seon-Hye;Kim, Young Jin;Jang, Hwan-Hee;Jung, Hyun-Ah;Hwang, Yu-Jin;Choe, Jeong-Sook;Kim, Jung-Bong
    • Korean Journal of Environmental Agriculture
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    • v.35 no.3
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    • pp.184-190
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    • 2016
  • BACKGROUND: Anthocyanins, potential health-promoting compounds, were major natural pigment in the blueberry (Vaccinium corymbosum L.). The objectives of this study was to investigate anthocyanin glycosides in the blueberry varieties.METHODS AND RESULTS: A total of seventeen anthocyanins were identified from highbush blueberry using HPLC (representatives, 530 nm) and ESI-MS in positive ion mode. The individual anthocyanins are containing cyanidin, delphinidin, malvidin, peonidin, and petunidin moieties which are acylated with aliphatic acid (acetic acid) and conjugated with sugar moieties (arabinose, galactose, and glucose). Among them, delphinidin 3-O-galactoside (D3Ga), peonidin 3-O-glucoside (Pn3G) + malvidin 3-O-galactoside (M3Ga) were major compounds in varieties. Total anthocyanins were found the highest level in 'Elizabeth' (1,406.3 mg/100 g dry weight) which was 3-fold higher than 'Darrow' (465.7). Especially, D3Ga was presented the 32% of total anthocyanins followed by Pn3G + M3Ga (20%) in 'Elizabeth'.CONCLUSION: This result was showed as valuable information regarding nutritional properties of the different varieties of the highbush blueberry.

Literature Study on Jaundice of Kum-Won Sa Dae Ga (금원사대가(金元四大家)의 황달(黃疸)에 대한 문헌적 고찰)

  • Song, Jeong-Ho;Kim, Soo-Sung;Kim, Byung-Min;Na, Min-Soo;Liu, Chiian-Hai;Yoon, Hyuk;Jeong, Heon-Young;Kim, Kang-San
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.6
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    • pp.1331-1346
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    • 2008
  • The aim of this study was to establish opinions of Kum Won Sa dea ga on jaundice and find out clinical significance. Contents dealing with jaundice were searched manually in works of Kum Won Sa dea ga. Those were translated into Korean and studied. Yoo wan so(劉完素) had opinion that jaundice is induced by dampness with heatness(濕熱) or dryness with heatness(濕熱) and should be treated with diuretics and laxatives. Jang jong jung(張從政) had opinion that jaundice is induced by spleen(脾) mainly and should be treated with diaphoretics, emetics, laxatives. Lee dong won(李東垣) had opinion that jaundice is induced by mistaken diaphoretics, dysfunction of spleen(脾), heatness(熱) and treatments should depend on six meridian pathways(六經). Ju jin hyeong(朱震亨) had opinion that jaundice is induced by dampness with heatness(濕熱) and coldness with dampness(濕熱) and should be treated with diuretics and detoxicant. Kum Won Sa dae ga thought jaundice in induced by dampness with heatness(濕熱) and explained pathology by the five viscera and the six entrails(五臟六腑). And they treated patients with jaundice according to etiologic source.

Influence of Series Resistance and Interface State Density on Electrical Characteristics of Ru/Ni/n-GaN Schottky structure

  • Reddy, M. Siva Pratap;Kwon, Mi-Kyung;Kang, Hee-Sung;Kim, Dong-Seok;Lee, Jung-Hee;Reddy, V. Rajagopal;Jang, Ja-Soon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.13 no.5
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    • pp.492-499
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    • 2013
  • We have investigated the electrical properties of Ru/Ni/n-GaN Schottky structure using current-voltage (I-V) and capacitance-voltage (C-V) measurements at room temperature. The barrier height (${\Phi}_{bo}$) and ideality factor (n) of Ru/Ni/n-GaN Schottky structure are found to be 0.66 eV and 1.44, respectively. The ${\Phi}_{bo}$ and the series resistance ($R_S$) obtained from Cheung's method are compared with modified Norde's method, and it is seen that there is a good agreement with each other. The energy distribution of interface state density ($N_{SS}$) is determined from the I-V measurements by taking into account the bias dependence of the effective barrier height. Further, the interface state density $N_{SS}$ as determined by Terman's method is found to be $2.14{\times}10^{12}\;cm^{-2}\;eV^{-1}$ for the Ru/Ni/n-GaN diode. Results show that the interface state density and series resistance has a significant effect on the electrical characteristics of studied diode.

W-Band Power Amplifier with Hybrid Bias Network Using 60-nm GaN pHMET Process (하이브리드 바이어스 네트워크가 적용된 W대역 60-nm GaN pHEMT 전력 증폭기)

  • Yoo, Jinho;Lee, Jaeyong;Jang, Seongjin;Jung, Hayeon;Kim, Kichul;Choi, Jeung Won;Park, Juman;Park, Changkun
    • Journal of IKEEE
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    • v.26 no.1
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    • pp.77-82
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    • 2022
  • The effect of the bias network on the performance of the W-band power amplifier(PA) was investigated. The performances of the typical RC and radial stub networks were examined, and a hybrid network was proposed for W-band application and its performance was confirmed. To verify this, a W-band PA was designed using a 60-nm GaN pHEMT process. When hybrid networks were applied, the PA had improved stability in all frequency bands, secured about 9 dB of power gain at operating frequencies 87 GHz to 93 GHz, and the maximum PAE was found to be about 12.3% at output power of 26.7 dBm.

JANG-YOOK-DANG's and Irreverence by casting upon the world (장육당(藏六堂)의 육가(六歌)와 완세불공(玩世不恭))

  • Yoon, Yoeng-Ok
    • Sijohaknonchong
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    • v.25
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    • pp.101-127
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    • 2006
  • JANG-YOOK-DANG(장육당) is the pen-name of Lee, Byeol(이별). His elder brother is Lee, won(이원). He was putted to death by the king Yeon-san(연산군). So abandoning the way of the world, JANG-YOOK-DANG hided himself at mountain valley in Peong-san of Hwng-haedo(황해도 평산). Here he angled for fish and with the persons over sixty years old drunk, sang the songs. Then he composed the poem . This poem spreaded abroad, and came to the ears of Lee, Hwang(이황). He criticized this poem to have irreverence by casting upon the world, not to have gentleness and affability. But imitating the poem he composed intended to be sung. For that gentleness and affability are the instruction of the Poetry, he filled the poems with contents of the gentleness and the affability. But the livings of the two persons were different, and then their poems was intended to be sung were different. In these different contents, we can not say that this or that is right. JANG-YOOK-DANG would do to express his bitter sentiments by his song.

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Effects of Gibberellic Acid and Alternating Temperature on Breaking Seed Dormancy of Panax ginseng C. A. Meyer (개갑된 인삼종자 휴면 조기타파에 미치는 GA3 및 변온처리 효과)

  • Lee, Jung Woo;Kim, Young Chang;Kim, Jang Uk;Jo, Ick Hyun;Kim, Kee Hong;Kim, Dong Hwi
    • Korean Journal of Medicinal Crop Science
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    • v.24 no.4
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    • pp.284-293
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    • 2016
  • Background: Developing new ginseng cultivars is a significant time-consuming process owing to the three years of growth required for ginseng to flower. To shorten the ginseng breeding process, it is necessary to establish rapid progression through each generation. In this study, we examined it was possible to rapidly break ginseng seed dormancy using gibberellic acid ($GA_3$) treatment and alternating temperature. Methods and Results: Seeds were obtained from local variety. Seeds were treated with either $GA_3$ at a concentration of $100mg/{\ell} $, constant temperature ($-2^{\circ}C$ and $2^{\circ}C$), alternating temperature ($2^{\circ}C$ followed by $-2^{\circ}C$, followed by $2^{\circ}C$) or a combination $GA_3$ and temperature treatment. Following experimental treatment, seeds were sown into trays and placed in a greenhouse. Low germination rates were observed in seeds that did not receive $GA_3$ treatment, which were similar following $2^{\circ}C$ and $-2^{\circ}C$ constant temperature treatment. Germination rates increased in proportion to $GA_3$ and more so when combined with alternating temperature treatment. In additon, stem and leaf lengths of the resulting ginseng plants were increased following $GA_3$ treatment, although no synergistic effect was observed with alternating temperature treatment. Conclusions: These results suggest that a combination $GA_3$ and alternating temperature treatment enhances ginseng seed germination, which can contribute to shortening the time required to progress through a single ginseng generation for breeding.

Utility of a multiplex reverse transcriptase-polymerase chain reaction assay (HemaVision) in the evaluation of genetic abnormalities in Korean children with acute leukemia: a single institution study

  • Kim, Hye-Jin;Oh, Hyun Jin;Lee, Jae Wook;Jang, Pil-Sang;Chung, Nack-Gyun;Kim, Myungshin;Lim, Jihyang;Cho, Bin;Kim, Hack-Ki
    • Clinical and Experimental Pediatrics
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    • v.56 no.6
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    • pp.247-253
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    • 2013
  • Purpose: In children with acute leukemia, bone marrow genetic abnormalities (GA) have prognostic significance, and may be the basis for minimal residual disease monitoring. Since April 2007, we have used a multiplex reverse transcriptase-polymerase chain reaction tool (HemaVision) to detect of GA. Methods: In this study, we reviewed the results of HemaVision screening in 270 children with acute leukemia, newly diagnosed at The Catholic University of Korea from April 2007 to December 2011, and compared the results with those of fluorescence in situ hybridization (FISH), and G-band karyotyping. Results: Among the 270 children (153 males, 117 females), 187 acute lymphoblastic leukemia and 74 acute myeloid leukemia patients were identified. Overall, GA was detected in 230 patients (85.2%). HemaVision, FISH, and G-band karyotyping identified GA in 125 (46.3%), 126 (46.7%), and 215 patients (79.6%), respectively. TEL-AML1 (20.9%, 39/187) and AML1-ETO (27%, 20/74) were the most common GA in ALL and AML, respectively. Overall sensitivity of HemaVision was 98.4%, with false-negative results in 2 instances: 1 each for TEL-AML1 and MLL-AF4. An aggregate of diseases-specific FISH showed 100% sensitivity in detection of GA covered by HemaVision for actual probes utilized. G-band karyotype revealed GA other than those covered by HemaVison screening in 133 patients (49.3%). Except for hyperdiplody and hypodiploidy, recurrent GA as defined by the World Health Organizationthat were not screened by HemaVision, were absent in the karyotype. Conclusion: HemaVision, supported by an aggregate of FISH tests for important translocations, may allow for accurate diagnosis of GA in Korean children with acute leukemia.