• Title/Summary/Keyword: Chung-Seo

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Design of Charge Pumping Circuit for LCD Driver IC (LCD Driver IC용 Charge Pumping 회로 설계)

  • Kwon, Yong-Jung;Kim, Hak-Yun;Seo, Sang-Jo;Choi, Ho-Yong
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.575-576
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    • 2008
  • This paper presents a design of a charge pumping circuit for LCD Driver IC. The charge pumping circuit consists of a control block, a VCIOUT generating block, a DDVDH generating block, a VGH/VGL generating block, and VCL generating block. It generates various higher and lower voltage than supply voltage using external control input. Simulation results show that voltages of DDVDH, VGH, VGL, and VCL satisfy the target voltage, and the output DDVDH drives the output current 7mA.

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A Characteristic Improvement for the Parallel operation of Z-source Inverters (Z-소스 인버터의 병렬 운전 특성 개선)

  • Kim Y.H.;Mun Hyeon-Uk;Lee W.Y.;Seo K.M.;Won C.Y.
    • Proceedings of the KIPE Conference
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    • 2006.06a
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    • pp.281-284
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    • 2006
  • 본 논문에서는 연료 전지 시스템을 위한 Z-소스 인버터로 구성된 병렬 운전 시스템을 제시 하였다. PWM 방식으로는 Carrier phase shifted SPWM을 적용하였으며 이 방식은 출력 전류의 고조파 성분을 줄일 수 있는 장점을 갖는다. 그러나 이 기법을 Z-소스 인버터로 구성된 병렬 운전 시스템에 적용하는 경우 추가적으로 순환 전류를 발생한다. Z-소스 인버터로 구성된 병렬 운전 시스템이 동작 시 발생하는 순환 전류를 감소시키며, 부하전류에 낮은 고조파 성분을 가질 수 있도록 커플링된 순환 전류 리액터를 사용하였다. 이에 대한 적합성을 시뮬레이션을 통해 입증하였다.

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The Monitoring system for the measurement of the operating performance of a LIM which can be drive a new vehicle (신교통 차량 추진용 리니어모터의 운전성능측정 및 모니터링시스템 구축)

  • Jang, S.M.;Park, Y.T.;Seo, J.H.;Jeong, S.S.;Lee, S.H.;Ham, S.Y.;Park, C.I.;Jeong, R.G.;Lee, J.
    • Proceedings of the KIEE Conference
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    • 1997.07a
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    • pp.74-76
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    • 1997
  • This paper describes the implementation for electrical quanties and mechanical quanties monitoring system of the LIM driven by a inverter. The monitoring system can be display the characteristics of it's quanties, such as voltage, current, power, power factor, frequency, apparent power, thrust, speed, position, normal force, on the real time.

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Implementation of Eddystone-EID verification system using independent authentication server (독립 인증 서버를 이용한 Eddystone-EID 검증 시스템 구현)

  • Kang, Jin Su;Seo, Jeong Hun;Song, Ho Jong;Won, Yoo Jae
    • Proceedings of the Korea Information Processing Society Conference
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    • 2017.11a
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    • pp.1322-1325
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    • 2017
  • 최근 비콘을 이용하여 근거리에 있는 사용자를 찾아 다양한 혜택을 지원해주는 서비스가 제공되고 있다. 2016년에 Google은 보안성 강화를 위해 비콘의 고유 ID를 사용하는 것이 아닌, 주기적으로 변경되는 임시 ID를 사용하여 이를 암호화하고 Broadcasting 하는 Eddystone-EID(Ephemeral Identity)를 공개하였다. EID를 사용하기 위해서는 Google에 비콘의 정보를 등록하는 과정과 EID를 수신 후 Google을 통해 검증하는 과정이 필요하다. 이러한 이유로 외부 업체들도 EID를 사용하기 위해서는 Google에 비콘을 등록해야 하는 문제점이 발생한다. 이러한 문제점을 해결하기 위해 본 논문에서는 Eddystone-EID를 Google을 이용하지 않고 자체적으로 검증하는 방법을 제시한다.

A Fuel Cell System with Z-Source Inverters and Ultracapacitors (Z- 소스 인버터와 울트라커패시터를 이용한 연료 전지 시스템)

  • Kim, Y.H.;Moon, H.W.;Lee, W.Y.;Seo, K.M.;Won, C.Y.
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.350-353
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    • 2005
  • 본 논문에서는 연료 전지 전압의 왜란 보상을 위해 Z-소스 인버터와 울트라커패시터를 포함하는 연료 전지 시스템을 제안하였다. Z-소스 인버터는의 구조는 매우 간단하며 DC/DC 컨버터의 사용 없이 단순히 스위칭 패턴만을 제어하여 전압을 부스팅 할 수 있는 독특한 특징을 갖는다. 연료 전지시스템은 부하 변동시 외부적인 영향에 의해서 과도 상태 전압 왜란이 발생할 수 있다. 시뮬레이션결과는 Z소스 인버터와 울트라커패시터를 포함한 제안된 연료 전지 시스템이 시스템 과도 상태와 전압 왜란에 대해 안정된 응답을 갖고 동작 가능하다는 것을 보여 주었다.

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Comparison of Harmonic Detecting Methods For Sing-Phase Multi Level Active Power Filters (단상 멀티레벨 능동전력필터를 위한 고조파 검지 기법 비교)

  • Kim, Yoon-Ho;Kim, Soo-Hong;Kim, Sung-Min;Seo, Kang-Moon
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.494-497
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    • 2005
  • In this paper, harmonic detecting methods for the active power application are investigated. They are RDFT, Kalman Filter, Adaptive predictive filter, Instantaneous reactive power detecting method, Improved adaptive filter detecting method. The 5 harmonic detecting methods are simulated and their characteristics for the active filter application are compared using simulation results.

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Real-World Pointing Region Estimation Using 3D Geometry Information (3차원 기하학 정보를 이용한 실세계 지시 영역 추정)

  • Han, Yun-Sang;Seo, Yung-Ho;Doo, Kyoung-Soo;Choi, Jong-Soo
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.353-354
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    • 2007
  • This paper proposes the method which estimates the pointing region at the real world. This paper uses the technique to easily calibrate a camera of Z. Zhang. First, we calculate the projection matrix of each camera by the technique. Next, we estimate the location of the shoulder and the fingertip. Then we compute the pointing region in 3D real world by using projection matrix of each camera. Experiment result showed that the error between estimated point and the plane center point is less than 5cm.

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Photodynamic Therapy Combined with 1064-nm Nd:YAG Laser Therapy and Topical Efinaconazole for Refractory Onychomycosis: Case Series

  • Park, Jae Wan;Koh, Young Gue;Seo, Seong Jun;Park, Kui Young
    • Medical Lasers
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    • v.10 no.3
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    • pp.185-188
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    • 2021
  • Onychomycosis is the most common disease of the nail, with a worldwide prevalence of 5.5%. It causes local pain, paresthesia, and cosmetic problems and decreases the patients' quality of life. Conventional treatments include the administration of topical and systemic agents. However, factors such as subungual hyperkeratosis and biofilm formation may affect the efficacy of these treatments. Moreover, side effects associated with systemic agents are a major concern for patients. Therefore, various novel treatments are being developed; among them, photodynamic therapy (PDT) and Nd:YAG laser are promising, and several studies have demonstrated the efficacy and safety of PDT and laser therapy. Here, we report the efficacy and tolerability of PDT combined with 1064-nm Nd:YAG laser therapy and topical efinaconazole for the treatment of three patients with refractory onychomycosis.

α-Kleisin subunit of cohesin preserves the genome integrity of embryonic stem cells

  • Seobin Yoon;Eui-Hwan Choi;Seo Jung Park;Keun Pil Kim
    • BMB Reports
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    • v.56 no.2
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    • pp.108-113
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    • 2023
  • Cohesin is a ring-shaped protein complex that comprises the SMC1, SMC3, and α-kleisin proteins, STAG1/2/3 subunits, and auxiliary factors. Cohesin participates in chromatin remodeling, chromosome segregation, DNA replication, and gene expression regulation during the cell cycle. Mitosis-specific α-kleisin factor RAD21 and meiosis-specific α-kleisin factor REC8 are expressed in embryonic stem cells (ESCs) to maintain pluripotency. Here, we demonstrated that RAD21 and REC8 were involved in maintaining genomic stability and modulating chromatin modification in murine ESCs. When the kleisin subunits were depleted, DNA repair genes were downregulated, thereby reducing cell viability and causing replication protein A (RPA) accumulation. This finding suggested that the repair of exposed single-stranded DNA was inefficient. Furthermore, the depletion of kleisin subunits induced DNA hypermethylation by upregulating DNA methylation proteins. Thus, we proposed that the cohesin complex plays two distinct roles in chromatin remodeling and genomic integrity to ensure the maintenance of pluripotency in ESCs.

Roles of Virtual Memory T Cells in Diseases

  • Joon Seok;Sung-Dong Cho;Seong Jun Seo;Su-Hyung Park
    • IMMUNE NETWORK
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    • v.23 no.1
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    • pp.11.1-11.11
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    • 2023
  • Memory T cells that mediate fast and effective protection against reinfections are usually generated upon recognition on foreign Ags. However, a "memory-like" T-cell population, termed virtual memory T (TVM) cells that acquire a memory phenotype in the absence of foreign Ag, has been reported. Although, like innate cells, TVM cells reportedly play a role in first-line defense to bacterial or viral infections, their protective or pathological roles in immune-related diseases are largely unknown. In this review, we discuss the current understanding of TVM cells, focusing on their distinct characteristics, immunological properties, and roles in various immune-related diseases, such as infections and cancers.