RESEARCH ON DECREASE OF CELL TO MODULE LOSS FOR CRYSTALLINE SILICON PHOTOVOLTAIC MODULE

JungYup YANG,YoungKyoung AHN,PilHo HUH,Min PARK,MinGu KIM,JunYoung LEE,DongHun NO,YeonIl KANG,DongSeop KIM 한국신재생에너지학회 2012 AFORE Vol.2012 No.-

Performance of Open-Loop MIMO Precoder With Cross-Polarized Antennas Over Correlated Channels With an LOS Component

Jungyup Jang,Dong Ho Kim IEEE 2017 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Vol.16 No.6

<P>Open-loop multiple-input multiple-output (MIMO) precoders, that do not require channel information, were recently proposed to mitigate the performance degradation of spatial multiplexing (SM) due to spatial correlations and/or line-of-sight (LOS) component. The open-loop MIMO pre-coder technique has been adopted in next generation broadcasting systems, such as digital video broadcasting-next generation handheld (DVB-NGH) and advanced television systems committee (ATSC) 3.0 standards. Furthermore, in DVB-NGH and ATSC 3.0, cross-polarized antennas have been employed in order to overcome the insufficient antenna separation for co-polarized antennas, which can enhance the performance over high correlation and LOS conditions. In this paper, we analyze and evaluate the performance of the open-loop MIMO precoders with cross-polarized antennas over correlated channels with an LOS component. We first study the statistical property of the MIMO channel with cross-polarized antennas on the basis of the measurement-based channel model. Next, we derive pairwise error probability (PEP) of the SM with the open-loop MIMO precoder. Through the PEP derivation, we evaluate the performance of each open-loop MIMO precoder against the spatial correlations and LOS component with the effect of cross-polarized antennas. The simulation results are presented to demonstrate the performance of the open-loop MIMO precoders over various channel conditions.</P>

Observation of inverted hysteresis loops in cobalt nanoparticles fabrication by laser irradiation

JungYup Yang,JuHyung Kim,ChaeOk Kim,JinPyo Hong 한국자기학회 2006 한국자기학회 학술연구발표회 논문개요집 Vol.16 No.1

We have investigated negative remanence in Co NP system. TheCo NPs were uniquely fabricated by using a laser irradiation technique. Magnetization measurements performed on Co NP system show negative remanence taken at temperatures higher than 92 K. The observed negative remanence correlates to the blocking temperature of superparamagnetism. Although we have no clear explanation for negative remanence, this behavior is associated to the magnetic coupling characteristic between the ferromagnetic Co NP and superparamagnetic Co NP.

상관성이 존재하는 라이시안 채널 환경에서 이중편파안테나를 적용한 개루프 프리코더의 성능비교

장정엽(Jungyup Jang),김동호(Dong Ho Kim),이예훈(Ye Hoon Lee) 한국통신학회 2015 한국통신학회 학술대회논문집 Vol.2015 No.06

Enhancement of the photo conversion efficiencies in Cu(In,Ga)(Se,S)₂ solar cells fabricated by two-step sulfurization process

Yang, JungYup,Nam, Junggyu,Kim, Dongseop,Kim, GeeYeong,Jo, William,Kang, Yoonmook,Lee, Dongho American Institute of Physics 2015 Applied Physics Letters Vol.107 No.19

<P> Cu(In,Ga)(Se,S)<SUB>2</SUB> (CIGSS) absorber layers were fabricated by using a modified two-stage sputter and a sequential selenization/sulfurization method, and the sulfurization process is changed from one-step to two-step. The two-step sulfurization was controlled with two different H)<SUB>2</SUB>S gas concentrations during the sulfurization treatment. This two-step process yielded remarkable improvements in the efficiency (+0.7%), open circuit voltage (+14mV), short circuit current (+0.23mA/cm<SUP>2</SUP>), and fill factor (+0.21%) of a CIGSS device with 30×30cm<SUP>2</SUP> in size, owing to the good passivation at the grain boundary surface, uniform material composition among the grain boundaries, and modified depth profile of Ga and S. The deterioration of the P/N junction quality was prevented by the optimized S content in the CIGSS absorber layer. The effects of the passivation quality at the grain boundary surface, the material uniformity, the compositional depth profiles, the microstructure, and the electrical characteristics were examined by Kelvin probe force microscopy, X-ray diffraction, secondary ion mass spectrometry, scanning electron microscopy, and current-voltage curves, respectively. The two-step sulfurization process is experimentally found to be useful for obtaining good surface conditions and, enhancing the efficiency, for the mass production of large CIGSS modules. </P>

[Session 3] Contesting digital economy : The digital convergence of music in Korea

이정엽(Jungyup Lee) 한국방송학회 2008 한국방송학회 세미나 및 보고서 Vol.- No.-

이 논문은 디지털 테크놀로지를 이용한 음악 전송으로 인해 한국의 음악 경제와 음악 문화에 일어난 변화를 검토한다. 먼저 디지털 테크놀로지가 어떤 방식으로 음악 산업을 재편성 하고 있는지를 살펴본다. 1990년대 후반 ‘아이돌 스타 시스템’은 지배적인 테크놀로지적 매개였으나, 이제 산업적 재편성은 정보통신산업(ICTs)과 미디어/엔터테인먼트 산업을 가로질러 집중과 통합의 방향으로 전개되고 있다. 이런 관점에서 ‘디지털 경제’는 산업적인 과정으로서 자본주의의 심화를 향한다. 그러나 음악이 산업적으로 완전히 통제될 수 있는지 의문스럽다. 산업적 과정에 대한 검토는 보다 넓은 기술적 문화적 변화의 맥락 속에 자리잡아야 한다. 따라서 다음으로 우리가 음악과 관계 맺는 방식 그리고 우리가 서로 관계 맺는 방식이 디지털 테크놀로지로 인해 어떻게 영향 받는지를 논의한다. 디지털 테크놀로지는 개인적이고 사회적인 음악의 사용을 가속화하고 음악 문화의 다양화에 기여하는 것으로 논의되고 있다. 그러나 이러한 디지털 음악 문화의 잠재력이 산업적 재배치와 음악 비즈니스 실천에 의해 어떻게 제한되는지를 이해하는 것 또한 중요하다. 따라서 몇몇 인터넷 음악 서비스가 새로운 음악의 경험을 제공하고 그런 경험을 돈의 흐름으로 향하게 하려고 시도한다. 나는 이러한 산업적 재편이 음악의 문화적 변화와 영향을 주고 받음을 보여주고자 한다. 다시 말하면, 디지털 테크놀로지로 인한 새로운 음악적 경험은 음악 산업에게 있어서 새로운 비즈니스 기회임과 동시에, 음악 산업이 음악 문화의 복잡한 차원과 점점 직접 대면하도록 강제한다. 결론적으로 현재 진행되는 디지털화로 인해 음악 산업과 음악의 경험은 동시에 변형되며, 음악의 성격 자체는 재정의되고 경합된다. This paper examines the changes brought by digital technologies of music delivery in the music economy and culture in Korea. First, I look at how digital technologies impact the reorganization of music industry. The dominant technological mediation of the 'idol star system' in the late 1990s gives way to industrial reorganization toward concentration and integration across the information and communications technologies (ICTs) industries and the media/entertainment industries. It is suggested that the digital economy in this perspective is an industrial process toward deepening capitalism. However, I question how total and complete the industrial control of music. It needs to be located in the context of larger techno-cultural changes. Thus, secondly, I discuss how digital technologies impacts the way we relate to music and to each other. It is suggested that digital technologies accelerateonal persand social use of music and contribute to a diversified music culture. However, it is also important to get at how the potentials of digital music culture are limited and framed by the industrial rearrangement and business practices of music. Thus, lastly, by looking at the way in which a few leading internet music services attempt to provide new musical experiences and redirect them to business financial stream, I show how the industrial reorganization impacts and is impacted by cultural changes in music. In other words, new musical experiences brought by digital technologies provide new business opportunities to the revamped music industry on the one hand, they increasingly force the latter to cope with the complicated dimension of musical culture on the other. In conclusion, it is suggested that the ongoing digitalization radically transforms the music industry and music experiences at the same time, and renders the nature of music redefined and contested.

Open-Loop Precoder Design for Spatial Multiplexing Systems in Transmit Correlated MIMO Channels

Jang, Jungyup,Kim, Dong Ho,Lee, Ye Hoon,Seo, Jong-Soo IEEE 2017 IEEE Transactions on Vehicular Technology VT Vol.66 No.5

<P>The performance of spatial multiplexing (SM) systems is significantly degraded in transmit correlated multiple-input multiple-output (MIMO) channels. In communication systems that are available for feedback, precoding can enhance performance by exploiting channel state information (CSI) at the transmitter. However, broadcasting systems have no reverse channel nor any CSI. Furthermore, channel mismatches in communication systems severely affect performance. For these systems, open-loop precoders that require no feedback CSI were proposed. However, an analytical precoder design method was not presented in the previous works. In this paper, we present an open-loop precoder design method for SM systems with a maximum-likelihood receiver in transmit correlated MIMO channels. We first describe how to design an open-loop precoder using a rotational matrix over the amplitude of the correlation. Our precoder design method is derived by observing the effect of correlation mismatch between the feedback CSI and the actual channel condition on a minimum Euclidean distance-based precoder. Next, we present a method to design an open-loop precoder that takes into account the impact of the phase of the correlation. For this precoder, a phase rotation matrix is added on the rotational matrix, and optimum parameters are obtained by maximizing the worst-case minimum distance for the phase of the correlation. The simulation results illustrate the validity of proposed open-loop precoder in transmit correlated MIMO channels.</P>

데이터 생애주기 기반 표준화 현황 및 추진방안

오정엽(Jungyup OH) 한국통신학회 2021 한국통신학회 학술대회논문집 Vol.2021 No.11

최근 AI 기술 보편화 및 산업간 융합 활성화에 맞춰 데이터의 수집 및 가공부터 공유 및 유통에 이르기까지 데이터 전반에 걸친 표준화 요구되는 상황에서 데이터의 생애주기 및 주기별 표준화 현황과 그에 따른 표준화 추진방안에 대해 알아보고자 한다.

IMO 온실가스 감축 중장기 조치로써의 GHG 연료표준제도에 대한 고찰

이정엽(Jungyup Lee),박준성(Junesung Park),김회준(Hoijun Kim) 한국해양환경·에너지학회 2023 한국해양환경·에너지학회 학술대회논문집 Vol.2023 No.05

ISO/IEC JTC 1/SC 29(멀티미디어부호화) 주요 이슈 및 표준화 동향

오정엽(Jungyup OH) 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.11